High security fastener with buckled shroud retainer

ABSTRACT

An improved fastener comprising a fastener body having a tool-engaging portion, a threaded fastening portion and a shroud-receiving body portion; a shroud concentrically mounted on the shroud-receiving body portion and having an inner surface facing an outer surface of the shroud-receiving body portion; the inner surface of the shroud comprising an annular groove and the shroud-receiving body portion comprising a substantially arch-shaped axially-buckled radially-extending annular protrusion extending outwardly transverse to the central axis and disposed in the annular groove of the shroud; and the annular protrusion and annular groove of the shroud forming a shroud-retaining element restraining the shroud from movement in at least a first axial direction along the central axis such that the shroud will rotate relative to the fastener body under an applied external torque prior to the fastener body rotating when the fastener is engaged with an external structure at a design installation torque.

TECHNICAL FIELD

The present invention relates to high security fasteners, and moreparticularly to a high security fastener having a buckled shroudretainer.

BACKGROUND ART

Locking wheel nuts and wheel bolts are commonly used to attach wheels toaxel hub assemblies of automobiles and other vehicles. These fastenersare designed with security features that are intended to thwart theft byrendering the fasteners difficult to remove with conventional tools. Inparticular, the fasteners do not have the usual hexagonal head patternfound on conventional nuts and bolts and instead have smooth cylindricalsidewalls that cannot be gripped by standard wrenches. Fastener removalrequires the use of a special security tool having a unique key patternthat matches a corresponding groove pattern formed in the fastener endface.

Additional security can be obtained by fitting a free-spinning shroud orcap over the security fasteners cylindrical sidewalls, such that theshroud is in concentric relationship therewith. The shroud discouragesthe use of theft devices that could otherwise be used to grip thesidewalls and remove the fastener without an authorized security tool.Because the shroud substantially surrounds all exposed surfaces of thesidewalls, no rotational purchase can be obtained in the fastener. Thetheft device can only engage the shroud, which freely spins under actionof the theft device while the main body of the fastener remainsstationary.

Various systems have been developed for rotationally retaining theshroud or spin cap on the fastener body. For example, U.S. Pat. No.7,445,414, entitled “High Security Fastener Constructions,” is directedto a shroud fastener design having a shroud retaining system forretaining the shroud for rotation relative to the fastener body. Theentire contents and disclosure of U.S. Pat. No. 7,445,414 areincorporated herein by reference. International Patent Publication No.WO2004/001237, entitled “Screw-Threaded Fastening,” is directed to awheel nut having a fastener body and a spin cap or shroud which isretained on the fastener body by means of an outwardly flared endportion of the fastener body which is received within an undercuttriangular groove in the inner surface of the cap.

BRIEF SUMMARY

With parenthetical reference to corresponding parts, portions orsurfaces of the disclosed embodiment, merely for the purposes ofillustration and not by way of limitation, an improved fastener (15,115, 215, 315, 415, 515, 615, 715, 815, 915) is provided comprising afastener body (16, 116, 216, 316, 416, 516, 616, 716, 816, 916)orientated about a central axis (x-x); the fastener body having atool-engaging portion (17, 117, 217, 317, 417, 517, 617, 717, 817, 917)to which a driving torque may be applied and a threaded fasteningportion (18, 118, 218, 318, 418, 518, 618, 718, 818, 918) configured andarranged to mate with a corresponding threaded element; the fastenerbody having a shroud-receiving body portion (19, 119, 219, 319, 419,519, 619, 719, 819, 919) orientated about the central axis; a shroud(20, 120, 220, 320, 420, 520, 620, 720, 820, 920) concentrically mountedon the shroud-receiving body portion and having an inner surface facingan outer surface of the shroud-receiving body portion; the shroud beingsupported in rotatable relationship with the shroud-receiving bodyportion such that the shroud will rotate relative to the fastener bodyunder an applied external torque prior to the fastener body rotatingwhen the fastener is engaged with an external structure at a designinstallation torque; the inner surface of the shroud comprising anannular groove (40, 140, 240, 340, 440, 540, 640, 740, 840, 940)orientated transverse to the central axis; the shroud-receiving bodyportion comprising a substantially arch-shaped axially-buckledradially-extending annular protrusion (43, 143, 243, 343, 443, 543, 643,743, 843, 943) extending outwardly transverse to the central axis andhaving at least an annular apex (44, 144, 244, 344, 444, 544, 644, 744,844, 944) disposed in the annular groove of the shroud; and thesubstantially arch-shaped axially-buckled radially-extending annularprotrusion of the shroud-receiving body portion and the annular grooveof the shroud forming a shroud-retaining element restraining the shroudfrom movement in at least a first axial direction along the centralaxis.

The shroud-receiving body may comprise a thin-walled cylindrical tubularportion having an annular first body surface (26), and an annularshoulder (17) having an annular second body surface (24); the shroud maycomprise an annular shoulder portion having an annular first shroudsurface (38, 138, 238, 338, 438, 535, 635, 735, 835, 935), and anannular second shroud surface (30, 130, 230, 330, 430, 530, 630, 730,830, 930); and the first body surface may face the first shroud surfaceand the second body contact surface may face the second shroud surface.The second body surface (24) of the shroud-receiving body and the secondshroud surface (30, 130, 230, 330, 430, 530, 630, 730, 830, 930) of theshroud may be in an opposing orientation and form a secondshroud-retaining element restraining the shroud from movement in atleast a second axial direction along the central axis opposite to thefirst axial direction along the central axis. An end portion (42) of thethin-walled cylindrical tubular portion of the shroud-receiving bodythat is adjacent the annular first body surface of the shroud-receivingbody may be supported radially by an opposed inwardly-facing cylindricalsurface (37, 137, 237, 337, 437) of the shroud such that the end portionof the thin-walled cylindrical tubular portion of the shroud-receivingbody is restrained from deforming radially outwardly from the centralaxis by the opposed inwardly-facing cylindrical surface of the shroud.The annular groove (40, 140, 240, 340, 440) of the shroud may extendinto a medial portion of the inner surface of the shroud between thefirst shroud surface (38, 138, 238, 338, 438) and the second shroudsurface (30, 130, 230, 330, 430). The shroud-retaining element may beformed by an axial buckle of a medial portion (41) of the thin-walledcylindrical tubular portion of the shroud-receiving body radially intothe annular groove (40, 140, 240, 340, 440) of the shroud. The axialbuckle of the medial portion (41) of the thin-walled cylindrical tubularportion of the shroud-receiving body may be formed by a compressiveforce applied axially to the thin-walled cylindrical tubular portion ofthe shroud-receiving body by the first shroud surface (38, 138, 238,338, 438) of the shroud. The groove (40, 140, 240, 340, 440) of theshroud may comprise an annular first inner corner, an annular secondinner corner, an annular first outer edge with the inner surface of theshroud (31, 131, 231, 331, 431), and an annular second outer edge withthe inner surface (37, 137, 237, 337, 437) of the shroud. The annularfirst inner corner and/or the annular second inner corner of the groovemay comprise a frusto-conical surface (132, 136, 532, 534, 932, 934) ora radial surface (832). The annular first outer edge and/or the annularsecond outer edge of the groove may comprise a frusto-conical surface(32, 36, 632) or a radial surface. The annular groove of the shroud maycomprise a trapezoidal (140, 540, 940), triangular (340) orsemi-circular (440) cross-section taken in a plane extending radiallyfrom the central axis. The groove of the shroud may be substantiallyU-shaped (440) or V-shaped (340). The substantially arch-shapedaxially-buckled radially-extending annular protrusion of theshroud-receiving body portion may be asymmetrical (843). Thesubstantially arch-shaped axially-buckled radially-extending annularprotrusion of the shroud-receiving body portion may be substantiallyU-shaped (244, 444) or V-shaped (44, 344). The fastener body maycomprise a lock nut (16, 116, 216, 316, 416, 516, 616, 716, 816) or alock bolt (916).

In another aspect a fastener (1015, 1115) is provided comprising afastener body orientated about a central axis (x-x); the fastener bodyhaving a tool-engaging portion (1017, 1117) to which a driving torquemay be applied and a threaded fastening portion (1018, 1118) configuredand arranged to mate with a corresponding threaded element; the fastenerbody having a shroud-receiving body portion (1019, 1119) orientatedabout the central axis; a shroud (1020, 1120) concentrically mounted onthe shroud-receiving body portion and having an inner surface (1031,1131) facing an outer surface of the shroud-receiving body portion; theshroud being supported in rotatable relationship with theshroud-receiving body portion such that the shroud will rotate relativeto the fastener body under an applied external torque prior to thefastener body rotating when the fastener is engaged with an externalstructure at a design installation torque; the outer surface of theshroud-receiving body portion comprising an annular groove (1040, 1140)orientated transverse to the central axis; the shroud comprising asubstantially arch-shaped axially-buckled radially-extending annularprotrusion (1043, 1143) extending inwardly transverse to the centralaxis and having at least an annular apex (1044, 1144) disposed in theannular groove of the shroud-receiving body portion; and thesubstantially arch-shaped axially-buckled radially-extending annularprotrusion of the shroud and the annular groove of the shroud-receivingbody portion forming a shroud-retaining element restraining the shroudfrom movement in at least a first axial direction along the centralaxis.

The shroud-receiving body portion may comprise an annular shoulderhaving an annular body surface (1024, 1124); the shroud may comprise anannular first shroud surface (1030, 1130) and an annular second shroudsurface (1032, 1132); and the first shroud surface may face the bodysurface. The body surface of the shroud-receiving body portion and thefirst shroud surface of the shroud may be in an opposing orientation andform a second shroud-retaining element restraining the shroud frommovement in at least a second axial direction along the central axisopposite to the first axial direction along the central axis. The endportion (1045) of the shroud that is adjacent the first shroud surface(1030) of the shroud may be supported radially by an opposedoutwardly-facing cylindrical surface (1025) of the shroud-receiving bodyportion such that the end portion of the shroud is restrained fromdeforming radially inwardly toward the central axis by the opposedoutwardly-facing cylindrical surface of the shroud-receiving bodyportion. The shroud-receiving body portion may comprise an annularsecond body end surface (1059) and the annular groove (1040) of theshroud-receiving body portion may extend into a medial portion of theouter surface of the shroud-receiving body portion between the bodysurface and the second body surface. The shroud-retaining element may beformed by an axial buckle (1044) of a medial portion of the shroudradially into the annular groove (1040) of the shroud-receiving bodyportion (1019). The axial buckle (1040) of the medial portion of theshroud may be formed by a compressive force applied axially to theannular second shroud surface (1032) of the shroud. The shroud maycomprise a thinned tubular cylindrical portion (1041, 1145) axiallyaligned with the annular groove (1040, 1140) of the shroud-receivingbody portion and the shroud-retaining element may be formed by an axialbuckle (1043, 1143) of the thinned tubular cylindrical portion of theshroud radially into the annular groove of the shroud-receiving bodyportion. The thinned tubular cylindrical portion of the shroud maycomprise an annular crease (1036, 1136) and the annular apex (1044,1144) of the shroud-retaining element may be formed by an axial buckleof the thinned tubular cylindrical portion (1041, 1045) of the shroud atthe annular crease radially into the annular groove (1040, 1140) of theshroud-receiving body portion. The groove of the shroud-receiving bodyportion may comprise an annular first inner corner, an annular secondinner corner, an annular first outer edge with the outer surface of theshroud-receiving body portion, and an annular second outer edge with theouter surface of the shroud-receiving body portion. The annular firstinner corner and/or the annular second inner corner of the groove maycomprise a frusto-conical surface (1026, 1028, 1126, 1128) or a radialsurface. The annular first outer edge and/or the annular second outeredge of the groove may comprise a frusto-conical surface or a radialsurface. The annular groove of the shroud-receiving body portion maycomprise a trapezoidal, triangular or semi-circular cross-section takenin a plane extending radially from the central axis. The groove of theshroud-receiving body portion may be substantially U-shaped or V-shaped.The substantially arch-shaped axially-buckled radially-extending annularprotrusion of the shroud may be asymmetrical. The substantiallyarch-shaped axially-buckled radially-extending annular protrusion of theshroud may be substantially U-shaped or V-shaped. The fastener body maycomprise a lock nut or a lock bolt.

In another aspect, a fastener (1215, 1315, 1415) is provided comprisinga fastener body (1216, 1416) orientated about a central axis; thefastener body having a tool-engaging portion (1217, 1417) to which adriving torque may be applied and a threaded fastening portion (1218,1418) configured and arranged to mate with a corresponding threadedelement; the fastener body having a shroud-receiving body portion (1219,1419) orientated about the central axis; a shroud (1220, 1320, 1420)concentrically mounted on the shroud-receiving body portion and havingan inner surface facing an outer surface of the shroud-receiving bodyportion; the shroud being supported in rotatable relationship with theshroud-receiving body portion such that the shroud will rotate relativeto the fastener body under an applied external torque prior to thefastener body rotating when the fastener is engaged with an externalstructure at a design installation torque; the outer surface of theshroud-receiving body portion comprising an annular step (1225, 1226,1425, 1426) orientated transverse to the central axis; the shroudcomprising an axially-buckled radially-extending annular end portion(1244, 1344, 1443, 1444) bent inwardly transverse to the central axisand disposed in the annular step of the shroud-receiving body portion;and the bent end portion of the shroud and the annular step of theshroud-receiving body portion forming a shroud-retaining elementrestraining the shroud from movement in at least a first axial directionalong the central axis.

The shroud-receiving body portion may comprise a second annular step(1226, 1125); the shroud may comprise an annular flange (1245, 1345)disposed around the annular step of the shroud-receiving body portion;and the second annular step of the shroud-receiving body portion and theannular flange of the shroud may form a second shroud-retaining elementrestraining the shroud from movement in at least a second axialdirection along the central axis opposite to the first axial directionalong the central axis. The shroud may comprises a thinned tubularcylindrical portion (1242, 1342, 1442, 1445) axially aligned with theannular step of the shroud-receiving body portion and theshroud-retaining element may be formed by an axial buckle of the thinnedtubular cylindrical portion of the shroud radially around the annularstep of the shroud-receiving body portion. The thinned tubularcylindrical portion of the shroud may comprise an annular crease (1236,1336, 1436, 1466) and the shroud-retaining element may be formed by anaxial buckle of the thinned tubular cylindrical portion of the shroud atthe annular crease. The shroud-receiving body portion may comprise asecond annular step and the outer surface of the shroud-receiving bodyportion may comprise an annular notch or recess (1228, 1428) between theannular step (1225, 1425) and the second annular step (1226, 1426). Theouter surface of the shroud-receiving body portion may comprise a secondannular step (1425, 1426) orientated transverse to the central axis; theshroud may comprise a second axially-buckled radially-extending annularend portion (1443, 1444) bent inwardly transverse to the central axisand disposed around the second annular step of the shroud-receiving bodyportion; and the second bent end portion of the shroud and the secondannular step of the shroud-receiving body portion may form a secondshroud-retaining element restraining the shroud from movement in atleast a second axial direction along the central axis opposite to thefirst axial direction along the central axis. The shroud may comprise athinned tubular cylindrical portion (1442, 1445) axially aligned withthe second annular step (1425, 1426) of the shroud-receiving bodyportion and the second shroud-retaining element may be formed by anaxial buckle of the thinned tubular cylindrical portion of the shroudradially around the second annular step of the shroud-receiving bodyportion. The thinned tubular cylindrical portion of the shroud maycomprise an annular crease (1436, 1466) and the second shroud-retainingelement may be formed by an axial buckle of the thinned tubularcylindrical portion of the shroud at the annular crease. The fastenerbody may comprise a lock nut or a lock bolt.

In another aspect, a method of forming a fastener is provided comprisingthe steps of: providing a fastener body orientated about a central axis;the fastener body having a tool engaging portion to which a drivingtorque may be applied, a threaded fastening portion configured andarranged to mate with corresponding threaded element, and ashroud-receiving body portion orientated about the central axis;providing a shroud; mounting the shroud concentrically on theshroud-receiving body portion such that an inner surface of the shroudfaces an outer surface of the shroud-receiving body portion; axiallyaligning an annular groove in the inner surface of the shroud or theshroud receiving body with a buckling portion of the other of the shroudor the shroud-receiving body portion; restraining the fastener body frommoving in a first direction along the central axis; applying an axialforce to the shroud or the shroud-receiving body in the first directionsuch that the buckling portion buckles inwardly or outwardly into theannular groove under the applied axial force to form a substantiallyarch-shaped axially-buckled radially-extending annular protrusionextending transverse to the central axis and having at least an annularapex disposed in the annular groove; such that the shroud is restrainedfrom movement in at least one axial direction along the central axisthat is opposite to the first axial direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a first embodiment of an improvedsecurity fastener.

FIG. 2 is a perspective view of the security fastener shown in FIG. 1.

FIG. 3 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 1.

FIG. 4 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 1.

FIG. 5 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 1.

FIG. 6 is an enlarged detailed view of the security fastener shown inFIG. 5, taken generally within the indicated circle of FIG. 5.

FIG. 7 is a side elevation view of a second embodiment of an improvedsecurity fastener.

FIG. 8 is a perspective view of the security fastener shown in FIG. 7.

FIG. 9 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 7.

FIG. 10 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 7.

FIG. 11 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 7.

FIG. 12 is an enlarged detailed view of the security fastener shown inFIG. 11, taken generally within the indicated circle of FIG. 11.

FIG. 13 is a side elevation view of a third embodiment of an improvedsecurity fastener.

FIG. 14 is a perspective view of the security fastener shown in FIG. 13.

FIG. 15 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 13.

FIG. 16 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 13.

FIG. 17 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 13.

FIG. 18 is an enlarged detailed view of the security fastener shown inFIG. 17, taken generally within the indicated circle of FIG. 17.

FIG. 19 is a side elevation view of a fourth embodiment of an improvedsecurity fastener.

FIG. 20 is a perspective view of the security fastener shown in FIG. 19.

FIG. 21 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 19.

FIG. 22 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 19.

FIG. 23 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 19.

FIG. 24 is an enlarged detailed view of the security fastener shown inFIG. 23, taken generally within the indicated circle of FIG. 23.

FIG. 25 is a side elevation view of a fifth embodiment of an improvedsecurity fastener.

FIG. 26 is a perspective view of the security fastener shown in FIG. 25.

FIG. 27 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 25.

FIG. 28 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 25.

FIG. 29 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 25.

FIG. 30 is an enlarged detailed view of the security fastener shown inFIG. 29, taken generally within the indicated circle of FIG. 29.

FIG. 31 is a side elevation view of a sixth embodiment of an improvedsecurity fastener.

FIG. 32 is a perspective view of the security fastener shown in FIG. 31.

FIG. 33 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 31.

FIG. 34 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 31.

FIG. 35 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 31.

FIG. 36 is an enlarged detailed view of the security fastener shown inFIG. 35, taken generally within the indicated circle of FIG. 35.

FIG. 37 is a side elevation view of a seventh embodiment of an improvedsecurity fastener.

FIG. 38 is a perspective view of the security fastener shown in FIG. 37.

FIG. 39 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 37.

FIG. 40 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 37.

FIG. 41 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 37.

FIG. 42 is an enlarged detailed view of the security fastener shown inFIG. 41, taken generally within the indicated circle of FIG. 41.

FIG. 43 is a side elevation view of a eighth embodiment of an improvedsecurity fastener.

FIG. 44 is a perspective view of the security fastener shown in FIG. 43.

FIG. 45 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 43.

FIG. 46 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 43.

FIG. 47 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 43.

FIG. 48 is an enlarged detailed view of the security fastener shown inFIG. 47, taken generally within the indicated circle of FIG. 47.

FIG. 49 is a longitudinal vertical sectional view of the securityfastener shown in FIG. 43.

FIG. 50 is an enlarged detailed view of the security fastener shown inFIG. 49, taken generally within the indicated circle of FIG. 49.

FIG. 51 is a side elevation view of a ninth embodiment of an improvedsecurity fastener.

FIG. 52 is a perspective view of the security fastener shown in FIG. 51.

FIG. 53 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 51.

FIG. 54 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 51.

FIG. 55 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 51.

FIG. 56 is an enlarged detailed view of the security fastener shown inFIG. 55, taken generally within the indicated circle of FIG. 55.

FIG. 57 is a side elevation view of a tenth embodiment of an improvedsecurity fastener.

FIG. 58 is a perspective view of the security fastener shown in FIG. 57.

FIG. 59 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 57.

FIG. 60 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 57.

FIG. 61 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 57.

FIG. 62 is an enlarged detailed view of the security fastener shown inFIG. 61, taken generally within the indicated circle of FIG. 61.

FIG. 63 is a side elevation view of an eleventh embodiment of animproved security fastener.

FIG. 64 is a perspective view of the security fastener shown in FIG. 63.

FIG. 65 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 63.

FIG. 66 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 63.

FIG. 67 is an enlarged detailed view of the security fastener shown inFIG. 66, taken generally within the indicated circle of FIG. 66.

FIG. 68 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 63.

FIG. 69 is an enlarged detailed view of the security fastener shown inFIG. 68, taken generally within the indicated circle of FIG. 68.

FIG. 70 is a side elevation view of an twelfth embodiment of an improvedsecurity fastener.

FIG. 71 is a perspective view of the security fastener shown in FIG. 70.

FIG. 72 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 70.

FIG. 73 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 70.

FIG. 74 is an enlarged detailed view of the security fastener shown inFIG. 73, taken generally within the indicated circle of FIG. 73.

FIG. 75 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 70.

FIG. 76 is an enlarged detailed view of the security fastener shown inFIG. 75, taken generally within the indicated circle of FIG. 75.

FIG. 77 is a side elevation view of an thirteenth embodiment of animproved security fastener.

FIG. 78 is a perspective view of the security fastener shown in FIG. 77.

FIG. 79 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 77.

FIG. 80 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 77.

FIG. 81 is an enlarged detailed view of the security fastener shown inFIG. 80, taken generally within the indicated circle of FIG. 80.

FIG. 82 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 77.

FIG. 83 is an enlarged detailed view of the security fastener shown inFIG. 82, taken generally within the indicated circle of FIG. 82.

FIG. 84 is a side elevation view of an fourteenth embodiment of animproved security fastener.

FIG. 85 is a perspective view of the security fastener shown in FIG. 84.

FIG. 86 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 84.

FIG. 87 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 84.

FIG. 88 is an enlarged detailed view of the security fastener shown inFIG. 87, taken generally within the indicated circle of FIG. 87.

FIG. 89 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 84.

FIG. 90 is an enlarged detailed view of the security fastener shown inFIG. 89, taken generally within the indicated circle of FIG. 89.

FIG. 91 is a side elevation view of an fifteenth embodiment of animproved security fastener.

FIG. 92 is a perspective view of the security fastener shown in FIG. 91.

FIG. 93 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 91.

FIG. 94 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 91.

FIG. 95 is an enlarged detailed view of the security fastener shown inFIG. 94, taken generally within the indicated circle of FIG. 94.

FIG. 96 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 91.

FIG. 97 is an enlarged detailed view of the security fastener shown inFIG. 96, taken generally within the indicated circle of FIG. 96.

DETAILED DESCRIPTION OF THE EMBODIMENTS

At the outset, it should be clearly understood that like referencenumerals are intended to identify the same structural elements, portionsor surfaces consistently throughout the several drawing figures, as suchelements, portions or surfaces may be further described or explained bythe entire written specification, of which this detailed description isan integral part. Unless otherwise indicated, the drawings are intendedto be read (e.g., crosshatching, arrangement of parts, proportion,degree, etc.) together with the specification, and are to be considereda portion of the entire written description of this invention. As usedin the following description, the terms “horizontal”, “vertical”,“left”, “right”, “up” and “down”, as well as adjectival and adverbialderivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”,etc.), simply refer to the orientation of the illustrated structure asthe particular drawing figure faces the reader. Similarly, the terms“inwardly” and “outwardly” generally refer to the orientation of asurface relative to its axis of elongation, or axis of rotation, asappropriate.

Referring now to FIGS. 1-6, an improved safety fastener is provided, afirst nut-type embodiment of which is generally indicated at 15. Nutfastener 15 generally includes fastener body 16 and cap or shroud 20,which rotates about axis x-x relative to fastener body 16. Fastener body16 includes tool engaging portion 17, threaded fastening portion 18 andshroud-retaining post 19 on which shroud 20 is rotationally supported.

Threaded fastening portion 18 of fastener body 16 includes bore 21 thatis internally threaded over a portion or all of its length. Nut fastener15 may be installed in a wheel having a recess hole formed as arelatively deep cylindrical well. The wheel hole has an annular recessentrance and a wheel stud or post in the wheel hole, and fastener body16 and fastening portion 18 are sized and installed such that theinterior threads of inner bore 21 engage the corresponding exteriorthreads of the wheel stud in the wheel hole.

Tool engaging portion 17 of fastener body 16 extends radially outwardbetween fastening portion 18 and shroud-retaining post 19 and comprisesside wall 22 that is substantially cylindrical in shape. Side wall 22 isformed with a key-receiving pattern that may be implemented as a set ofcircumferentially arranged lock pattern grooves 23. Lock patternconfigurations that use formations of other grooves may also be used. Ascan be seen, lock pattern grooves 23 are visible on the annular frontface 24 of tool engaging portion 17 that lies between side wall 22 andshroud 20. In order to impart lock pattern uniqueness, lock patterngrooves 23 may be patterned or configured in any suitable alternativemanner, such as by employing a selected number of grooves and/or byvarying other features thereof, such as the spacing between groovesand/or the width, length, depth, profile or other configuration orfeature thereof. Such grooves are configured so that a corresponding key(no shown) may be used to engage lock pattern grooves 23. The keyincludes a socket and a drive portion and the entrance to the socket isformed with a key pattern that may be implemented as a set ofcircumferentially arranged key pattern lobes that are configured andarranged to engage the lock pattern grooves 23 when the socket is placedover the left end and shroud 20 of nut fastener 15. Thus, a key having amatching set of key pattern lobes may be used to engage lock patterngrooves 23 to actuate nut fastener 15 about axis x-x.

The security key is configured to fit within a gap space to engage thelock pattern and rotate nut fastener 15. Other tools either will not fitwithin the gap space or will not be able to properly engage and rotatenut fastener 15 when it is installed at its intended design installationtorque. The size of the gap can be controlled by sizing the diameter ofcylindrical sidewall 22 according to the diameter of the recess hole inwhich nut fastener 15 is employed. Tool engaging portion 17 is arrangedso that sidewall 22 is within the wheel hole. In this position, the nutfastener's lock pattern is only exposed inside the recessed wheel holeentrance. In this position, access to the nut fastener's lock pattern islimited by the circumferential gap space between the lock pattern'soutside diameter and the wheel hole's inside diameter. The ability ofshroud 20 to spin relative to fastener body 16 and fastening portion 18thereof provides a security feature that protects nut fastener 15 frombeing used as a purchase point for an unauthorized tools. Should anattempt be made to rotate nut fastener 15 by gripping the exposed end,cap 20 will tend to spin without any rotation being imparted to fastenerbody 16 and fastening portion 18 thereof.

Pre-assembled, as shown in FIG. 3, retaining post 19 of fastener body 16is a specially configured cylindrical member elongated along axis x-xand is generally bounded by leftwardly-facing vertical annular surface24, outwardly-facing horizontal cylindrical surface 25,leftwardly-facing annular vertical surface 26, and inwardly-facinghorizontal cylindrical surface 27. Surfaces 25, 26 and 27 generally forma thin-walled hollow cylindrical column of inner diameter 54, outerdiameter 55 and thickness 53, and comprise distal end portion 42, medialportion 41 and proximate portion 45.

Shroud 20 extends over and around shroud receiving post 19. As shown,shroud 20 includes inner bore 28, having inside diameter 56approximately the same size as outside diameter 55 of post 19 andcomprising specially configured annular groove 40. In particular, andwith reference to FIG. 3, inner bore 28 of shroud 20 has a generallycylindrical configuration elongated along axis x-x and is generallybounded by rightwardly-facing vertical annular surface 30,inwardly-facing horizontal cylindrical surface 31, leftwardly andinwardly-facing frusto-conical surface 32, leftwardly-facing verticalannular surface 33, inwardly-facing horizontal cylindrical surface 34,rightwardly-facing vertical annular surface 35, rightwardly andinwardly-facing frusto-conical surface 36, inwardly-facing horizontalcylindrical surface 37, and rightwardly-facing vertical circular surface38. Surfaces 32, 33, 34, 35 and 36 define annular groove 40 orientatedtransverse to axis x-x.

In the pre-assembled state shown in FIG. 4, shroud 20 has been placedover left distal end 42 of post 19 such that the outer annular portionof rightwardly-facing surface 38 of shroud 20 abuts againstleftwardly-facing annular end face 26 of end 42 of post 19. As shown, inthis pre-assembled state depth 52 of bore 28 of shroud 20 is dimensionedto provide gap 51 between rightwardly-facing annular end face 30 ofshroud 20 and annular end face 24 of fastener body 16. When assembled asdescribed below, gap 51 will disappear as medial portion 41 of post 19buckles outwardly into groove 40 and reduces the axial length along axisx-x of post 19 from end face 24 of body 16.

To complete assembly of fastener 15, with shroud 20 placed over leftdistal end 42 of post 19 such that the outer annular portion ofrightwardly-facing surface 38 of shroud 20 abuts againstleftwardly-facing annular end face 26 of end 42 of post 19 as shown inFIG. 4, an axial force is then applied with a ram to outerleftwardly-facing rounded surface 29 of shroud 20 while fastener body 16is held stationary in a press or the like. Such force is great enough todrive end face 38 of shroud 20 into end face 26 of fastener body 16 andbuckle medial portion 41 of cylindrical portion 19 into groove 40, asshown in FIGS. 5 and 6, which depict the fully assembled configurationof fastener 15. Thus, instead of deforming the cylindrical end 42 offastener body 16 into a groove, fastener body 16 and shroud 20 arespecially formed such that applying a directed axial force to shroud 20with a ram causes cylindrical medial portion 41 to buckle outwards intospecially formed groove 40 in shroud 20. Thus, distal end portion 42 andannular end face 26 of fastener post 19 are held so that they do notflare outwards. Instead, medial portion 41, which is axially inward fromend face 26 of fastener body 16, buckles into groove 40. As shown, theleft peripheral or distal end 42 of cylindrical post 19 of body 16 isradially supported or held in place by inwardly-facing cylindricalsurface 37 of shroud 20 so that peripheral end 42 does not deform orflare out. However, medial portion 41 of cylindrical end post 19, whichaligns axially with groove 40 of shroud 20, is not immediately supportedand has thickness 53 designed to buckle outwardly into groove 40 underthe applied force to form buckled retaining arch 43. When assembled, atleast apex 44 of buckled arch 43 extends into groove 40, therebyretaining shroud 20 on the end of body 16 such that shroud 20 is free torotate about center axis x-x of body 16 but is restrained from movingaxially to the left off of end 42 of post 19 and body 16. It has beenfound that buckled medial portion 43 of post 19, rather than a flaredend portion, results in a cap assembly that requires higher tear-offforces to remove and therefore is more secure. Thus, as shown in FIG. 6,substantially arched-shaped axially-buckled radially-extending annularprotrusion 43 is formed, which extends outwardly transverse to centralaxis x-x and has at least an annular apex 44 disposed in annular groove40 of shroud 20.

As shown in FIGS. 3 and 6, annular groove 40 in shroud 20 has an annularninety degree or squared first inner corner at the junction betweensurfaces 33 and 34, and an annular ninety degree or squared second innercorner at the junction between surfaces 34 and 35. Annular groove 40also has an annular first outer edge with inner surface 31 of shroud 20defined by frusto-conical surface 32, and an annular second outer edgewith inner surface 37 of shroud 20 defined by frusto-conical surface 36.Accordingly, surfaces 32 and 36 provide groove 40 with a chamfered outeredged groove, which helps to form a symmetrical arched-shapedaxially-buckled radially-extending annular protrusion 43 disposed inannular groove 40 of shroud 20 when medial portion 41 of cylindrical endpost 19 buckles outwardly into groove 40 under the applied axial ramforce. As shown, groove 40 therefor comprises a generally squarecross-sectional profile taken in a cross-sectional plane extendingradially from central axis x-x with chamfered outer edges.

Shroud 20 is thereby mounted concentrically on retaining post 19 of nutfastener 15 such that it does not move axially off of retaining post 19but is substantially free to rotate about axis x-x relative to fastenerbody 16. Although exterior surfaces 29 and 39 of shroud 20 are shown asbeing substantially rounded and cylindrical, respectively, other shapesor contours could also be used, such as hexagonal, square or entirelycylindrical. Moreover, although shroud 20 is shown as being closed endedon one side, alternatively it may have an open-ended configuration thatpartially exposes the end of post 19. If desired, shroud 20 may have adecorative finish to improve fastener appearance, including, but notlimited to, nickel/chrome plating, silver or gray coatings.

Turning now to FIGS. 7-12, a nut-type security fastener 115 according toa second example embodiment is shown. Fastener 115 has most of thefeatures of fastener 15 described above in connection with FIGS. 1-6.The major difference between fastener 115 and fastener 15 lies in thefact that groove 140 of shroud 120 of fastener 115 is formed with agenerally trapezoidal cross-sectional profile taken in a cross-sectionalplane extending radially from central axis x-x.

In particular, and with reference to FIGS. 9 and 11, inner bore 128 ofshroud 120 has a generally cylindrical configuration elongated alongaxis x-x and is generally bounded by rightwardly-facing vertical annularsurface 130, inwardly-facing horizontal cylindrical surface 131,leftwardly and inwardly-facing frusto-conical surface 132,inwardly-facing horizontal cylindrical surface 134, rightwardly andinwardly-facing frusto-conical surface 136, inwardly-facing horizontalcylindrical surface 137, and rightwardly-facing vertical circularsurface 138. Surfaces 132, 134, and 136 define annular groove 140orientated transverse to axis x-x.

As shown and described with respect to fastener 15, in the pre-assembledstate shown in FIG. 10, shroud 120 has been placed over left distal end42 of post 19 such that the outer annular portion of rightwardly-facingsurface 138 of shroud 120 abuts against leftwardly-facing annular endface 26 of end 42 of post 19. To complete assembly of fastener 115, withshroud 120 placed over left distal end 42 of post 19 such that the outerannular portion of rightwardly-facing surface 138 of shroud 120 abutsagainst leftwardly-facing annular end face 26 of end 42 of post 19 asshown in FIG. 10, an axial force is then applied with a ram to outerleftwardly-facing rounded surface 129 of shroud 120 while fastener body16 is held stationary in a press or the like. Such force is great enoughto buckle medial portion 41 of cylindrical portion 19 into groove 140,as shown in FIGS. 11 and 12, which depict the fully assembledconfiguration of fastener 115. Thus, medial portion 41, which is axiallyinward from end face 26 of fastener body 16, buckles into groove 140. Asshown, the left peripheral or distal end 42 of cylindrical post 19 ofbody 16 is radially supported or held in place by inwardly-facingcylindrical surface 137 of shroud 120 so that peripheral end 42 does notdeform or flare out. However, medial portion 41 of cylindrical end post19, which aligns axially with groove 140 of shroud 120, is notimmediately supported and has thickness 53 designed to buckle outwardlyinto groove 140 under the applied force to form buckled retaining arch143. When assembled, at least apex 144 of buckled arch 143 extends intogroove 140, thereby retaining shroud 120 on the end of body 16 such thatshroud 120 is free to rotate about center axis x-x of body 16 but isrestrained from moving axially to the left off of end 42 of post 19 andbody 16. Thus, as shown in FIG. 12, substantially arched-shapedaxially-buckled radially-extending annular protrusion 143 is formed,which extends outwardly transverse to central axis x-x and has at leastan annular apex 144 disposed in annular groove 140 of shroud 120.

As shown in FIGS. 9 and 12, annular groove 140 in shroud 120 has anannular obtuse first inner corner at the junction between surfaces 132and 134, and an annular obtuse second inner corner at the junctionbetween surfaces 134 and 136. Annular groove 140 also has an annularfirst outer edge with inner surface 131 of shroud 120 at the junctionbetween surfaces 131 and 132, and an annular second outer edge at thejunction between surfaces surface 136 and 137 of shroud 120.Accordingly, surfaces 132 and 136 provide groove 140 with a sloped edgedgroove, which helps to form arched-shaped axially-buckledradially-extending annular protrusion 143 disposed in annular groove 140of shroud 120 when medial portion 41 of cylindrical end post 19 bucklesoutwardly into groove 140 under the applied axial ram force. As shown,groove 140 therefor comprises a generally trapezoidal cross-sectionalprofile taken in a cross-sectional plane extending radially from centralaxis x-x.

Turning now to FIGS. 13-18, a nut-type security fastener 215 accordingto a third example embodiment is shown. Fastener 215 has most of thefeatures of fastener 15 described above in connection with FIGS. 1-6.The major difference between fastener 215 and fastener 15 lies in thefact that groove 240 of shroud 220 of fastener 215 is formed with agenerally rectangular cross-sectional profile taken in a cross-sectionalplane extending radially from central axis x-x.

In particular, and with reference to FIGS. 15 and 18, inner bore 228 ofshroud 220 has a generally cylindrical configuration elongated alongaxis x-x and is generally bounded by rightwardly-facing vertical annularsurface 230, inwardly-facing horizontal cylindrical surface 231,leftwardly-facing vertical annular surface 232, inwardly-facinghorizontal cylindrical surface 234, rightwardly-facing vertical annularsurface 236, inwardly-facing horizontal cylindrical surface 237, andrightwardly-facing vertical circular surface 238. Surfaces 232, 234, and236 define annular groove 240 orientated transverse to axis x-x.

As shown and described with respect to fastener 15, in the pre-assembledstate shown in FIG. 16, shroud 220 has been placed over left distal end42 of post 19 such that the outer annular portion of rightwardly-facingsurface 238 of shroud 220 abuts against leftwardly-facing annular endface 26 of end 42 of post 19. To complete assembly of fastener 215, withshroud 220 placed over left distal end 42 of post 19 such that the outerannular portion of rightwardly-facing surface 238 of shroud 220 abutsagainst leftwardly-facing annular end face 26 of end 42 of post 19 asshown in FIG. 16, an axial force is then applied with a ram to outerleftwardly-facing rounded surface 229 of shroud 220 while fastener body16 is held stationary in a press or the like. Such force is great enoughto buckle medial portion 41 of cylindrical portion 19 into groove 240,as shown in FIGS. 17 and 18, which depict the fully assembledconfiguration of fastener 215. Thus, medial portion 41, which is axiallyinward from end face 26 of fastener body 16, buckles into groove 240. Asshown, the left peripheral or distal end 42 of cylindrical post 19 ofbody 16 is radially supported or held in place by inwardly-facingcylindrical surface 237 of shroud 220 so that peripheral end 42 does notdeform or flare out. However, medial portion 41 of cylindrical end post19, which aligns axially with groove 240 of shroud 220, is notimmediately supported and has thickness 53 designed to buckle outwardlyinto groove 240 under the applied force to form buckled retaining arch243. When assembled, at least flattened apex 244 of buckled arch 243extends into groove 240, thereby retaining shroud 220 on the end of body16 such that shroud 220 is free to rotate about center axis x-x of body16 but is restrained from moving axially to the left off of end 42 ofpost 19 and body 16. Thus, as shown in FIG. 18, substantiallyarched-shaped axially-buckled radially-extending annular protrusion 243is formed, which extends outwardly transverse to central axis x-x andhas at least an annular apex 244 disposed in annular groove 240 ofshroud 220. Annular apex 244 in this embodiment is flattened as shown.

As shown in FIGS. 15 and 18, annular groove 240 in shroud 220 has anannular ninety degree or squared first inner corner at the junctionbetween surfaces 232 and 234, and an annular ninety degree or squaredsecond inner corner at the junction between surfaces 234 and 236.Annular groove 240 also has an annular ninety degree or squared firstouter edge with inner surface 231 of shroud 220 at the junction betweensurfaces 231 and 232, and an annular ninety degree or squared secondouter edge at the junction between surfaces surface 236 and 237 ofshroud 220 at the junction between surfaces 236 and 237 of shroud 220.Accordingly, surfaces 232, 234 and 236 help to form arched-shapedaxially-buckled radially-extending annular protrusion 243 disposed inannular groove 240 of shroud 220 when medial portion 41 of cylindricalend post 19 buckles outwardly into groove 240 under the applied axialram force. As shown, groove 240 therefor comprises a generallyrectangular cross-sectional profile taken in a cross-sectional planeextending radially from central axis x-x.

Turning now to FIGS. 19-24, a nut-type security fastener 315 accordingto a fourth example embodiment is shown. Fastener 315 has most of thefeatures of fastener 15 described above in connection with FIGS. 1-6.The major difference between fastener 315 and fastener 15 lies in thefact that groove 340 of shroud 320 of fastener 315 is formed with agenerally V-shaped cross-sectional profile taken in a cross-sectionalplane extending radially from central axis x-x.

In particular, and with reference to FIGS. 21 and 24, inner bore 328 ofshroud 320 has a generally cylindrical configuration elongated alongaxis x-x and is generally bounded by rightwardly-facing vertical annularsurface 330, inwardly-facing horizontal cylindrical surface 331,leftwardly and inwardly-facing frusto-conical surface 332, rightwardlyand inwardly-facing frusto-conical surface 336, inwardly-facinghorizontal cylindrical surface 337, and rightwardly-facing verticalcircular surface 338. Surfaces 332 and 336 define annular groove 340orientated transverse to axis x-x.

As shown and described with respect to fastener 15, in the pre-assembledstate shown in FIG. 22, shroud 320 has been placed over left distal end42 of post 19 such that the outer annular portion of rightwardly-facingsurface 338 of shroud 320 abuts against leftwardly-facing annular endface 26 of end 42 of post 19. To complete assembly of fastener 315, withshroud 320 placed over left distal end 42 of post 19 such that the outerannular portion of rightwardly-facing surface 338 of shroud 320 bearsagainst leftwardly-facing annular end face 26 of end 42 of post 19 asshown in FIG. 22, an axial force is then applied with a ram to outerleftwardly-facing rounded surface 329 of shroud 320 while fastener body16 is held stationary in a press or the like. Such force is great enoughto buckle medial portion 41 of cylindrical portion 19 into groove 340,as shown in FIGS. 23 and 24, which depict the fully assembledconfiguration of fastener 315. Thus, medial portion 41, which is axiallyinward from end face 26 of fastener body 16, buckles into groove 340. Asshown, the left peripheral or distal end 42 of cylindrical post 19 ofbody 16 is radially supported or held in place by inwardly-facingcylindrical surface 337 of shroud 320 so that peripheral end 42 does notdeform or flare out. However, medial portion 41 of cylindrical end post19, which aligns axially with groove 340 of shroud 320, is notimmediately supported and has thickness 53 designed to buckle outwardlyinto groove 340 under the applied force to form buckled retaining arch343. When assembled, pointed apex 344 of buckled arch 343 extends intogroove 340, thereby retaining shroud 320 on the end of body 16 such thatshroud 320 is free to rotate about center axis x-x of body 16 but isrestrained from moving axially to the left off of end 42 of post 19 andbody 16. Thus, as shown in FIG. 24, substantially arched-shapedaxially-buckled radially-extending annular protrusion 343 is formed,which extends outwardly transverse to central axis x-x and has at leastan annular pointed apex 344 disposed in annular groove 340 of shroud320. As shown, in this embodiment arched-shaped axially-buckledradially-extending annular protrusion 343 is generally V-shaped.

As shown in FIGS. 21 and 24, annular groove 340 in shroud 320 has asingle annular acute inner corner at the junction between surfaces 332and 336, and an annular first outer edge with inner surface 331 ofshroud 320 at the junction between surfaces 331 and 332, and an annularsecond outer edge at the junction between surfaces surface 336 and 337of shroud 320. Accordingly, surfaces 332 and 336 provide groove 340 witha sloped edged groove, which helps to form arched-shaped axially-buckledradially-extending annular protrusion 343 disposed in annular groove 340of shroud 320 when medial portion 41 of cylindrical end post 19 bucklesoutwardly into groove 340 under the applied axial ram force. As shown,groove 340 therefor comprises a generally V-shaped cross-sectionalprofile taken in a cross-sectional plane extending radially from centralaxis x-x.

Turning now to FIGS. 25-30, a nut-type security fastener 415 accordingto a fifth example embodiment is shown. Fastener 415 has most of thefeatures of fastener 15 described above in connection with FIGS. 1-6.The major difference between fastener 415 and fastener 15 lies in thefact that groove 440 of shroud 420 of fastener 415 is formed with agenerally U-shaped cross-sectional profile taken in a cross-sectionalplane extending radially from central axis x-x.

In particular, and with reference to FIGS. 27 and 30, inner bore 428 ofshroud 420 has a generally cylindrical configuration elongated alongaxis x-x and is generally bounded by rightwardly-facing vertical annularsurface 430, inwardly-facing horizontal cylindrical surface 431,inwardly-facing semi-circular radial surface 434, inwardly-facinghorizontal cylindrical surface 437, and rightwardly-facing verticalcircular surface 438. Surface 434 defines annular groove 440 orientatedtransverse to axis x-x.

As shown and described with respect to fastener 15, in the pre-assembledstate shown in FIG. 28, shroud 420 has been placed over left distal end42 of post 19 such that the outer annular portion of rightwardly-facingsurface 438 of shroud 420 abuts against leftwardly-facing annular endface 26 of end 42 of post 19. To complete assembly of fastener 415, withshroud 420 placed over left distal end 42 of post 19 such that the outerannular portion of rightwardly-facing surface 438 of shroud 420 bearsagainst leftwardly-facing annular end face 26 of end 42 of post 19 asshown in FIG. 28, an axial force is then applied with a ram to outerleftwardly-facing rounded surface 429 of shroud 420 while fastener body16 is held stationary in a press or the like. Such force is great enoughto buckle medial portion 41 of cylindrical portion 19 into groove 440,as shown in FIGS. 29 and 30, which depict the fully assembledconfiguration of fastener 415. Thus, medial portion 41, which is axiallyinward from end face 26 of fastener body 16, buckles into groove 440. Asshown, the left peripheral or distal end 42 of cylindrical post 19 ofbody 16 is radially supported or held in place by inwardly-facingcylindrical surface 437 of shroud 420 so that peripheral end 42 does notdeform or flare out. However, medial portion 41 of cylindrical end post19, which aligns axially with groove 440 of shroud 420, is notimmediately supported and has thickness 53 designed to buckle outwardlyinto groove 440 under the applied force to form buckled curved retainingarch 443. When assembled, curved apex 444 of buckled arch 443 extendsinto groove 440, thereby retaining shroud 420 on the end of body 16 suchthat shroud 420 is free to rotate about center axis x-x of body 16 butis restrained from moving axially to the left off of end 42 of post 19and body 16. Thus, as shown in FIG. 30, substantially arched-shapedaxially-buckled radially-extending annular protrusion 443 is formed,which extends outwardly transverse to central axis x-x and has at leastan annular curved apex 444 disposed in annular groove 440 of shroud 420.As shown, in this embodiment arched-shaped axially-buckledradially-extending annular protrusion 443 is generally U-shaped.

As shown in FIGS. 27 and 30, annular groove 440 in shroud 420 has asingle annular inner radius, and an annular first outer edge with innersurface 431 of shroud 420 at the junction between surfaces 431 and 434,and an annular second outer edge at the junction between surfacessurface 434 and 437 of shroud 420. Accordingly, surface 434 providesgroove 340 with a semicircular groove, which helps to form arched-shapedaxially-buckled radially-extending annular protrusion 443 disposed inannular groove 440 of shroud 420 when medial portion 41 of cylindricalend post 19 buckles outwardly into groove 440 under the applied axialram force. As shown, groove 440 therefor comprises a generally U-shapedor semi-circular cross-sectional profile taken in a cross-sectionalplane extending radially from central axis x-x.

Turning now to FIGS. 31-36, a nut-type security fastener 515 accordingto a sixth example embodiment is shown. Fastener 515 has most of thefeatures of fastener 115 described above in connection with FIGS. 7-12.The major difference between fastener 515 and fastener 115 lies in thefact that shroud 520 of fastener 515 is not entirely closed ended andannular groove 540 is aligned with end portion 542 of post 519.

In particular, and with reference to FIGS. 33 and 36, shroud 520 has agenerally cylindrical configuration elongated along axis x-x and isgenerally bounded by outwardly-facing horizontal cylindrical surface529, rightwardly-facing vertical annular surface 530, inwardly-facinghorizontal cylindrical surface 531, leftwardly and inwardly-facingfrusto-conical surface 532, inwardly-facing horizontal cylindricalsurface 533, rightwardly and inwardly-facing frusto-conical surface 534,rightwardly-facing vertical annular surface 535, inwardly-facinghorizontal cylindrical surface 536, leftwardly-facing vertical annularsurface 537, inwardly-facing horizontal cylindrical surface 538, andleftwardly-facing vertical annular surface 539, joined on it outsmarginal end to the left marginal end of surface 529. Through-bore 528of shroud 520 extends axially through both sides of shroud 520 and isdefined by surfaces 531-538. Surfaces 532, 533, and 534 define annulargroove 540 orientated transverse to axis x-x.

As shown and described with respect to fastener 115, in thepre-assembled state shown in FIG. 34, shroud 520 has been placed overleft distal end 42 of post 19 such that the outer annular portion ofrightwardly-facing annular face 535 of shroud 520 abuts againstleftwardly-facing annular end face 26 of end 42 of post 19. To completeassembly of fastener 515, with shroud 520 placed over left distal end 42of post 19 such that the outer annular portion of rightwardly-facingannular face 535 of shroud 520 abuts against and contactsleftwardly-facing annular end face 26 of end 42 of post 19 as shown inFIG. 34, an axial force is then applied with a ram to leftwardly-facingvertical annular surface 539 of shroud 520 while fastener body 16 isheld stationary in a press or the like. Such force is great enough tobuckle end portion 42 of cylindrical portion 19 into groove 540, asshown in FIGS. 35 and 36, which depict the fully assembled configurationof fastener 515. As shown, leftwardly-facing annular end face 26 of post19 is radially supported by frictional contact with rightwardly-facingannular face 535 of shroud 520 so that leftwardly-facing annular endface 26 of peripheral end 42 does not flare out. However, that portionof cylindrical end post 19 that aligns axially with groove 540 of shroud520, is not immediately supported and has thickness 53 designed tobuckle outwardly into groove 540 under the applied force to form buckledretaining arch 543. When assembled, at least apex 544 of buckled arch543 extends into groove 540, thereby retaining shroud 520 on the end ofbody 16 such that shroud 520 is free to rotate about center axis x-x ofbody 16 but is restrained from moving axially to the left off of end 42of post 19 and body 16. Thus, as shown in FIG. 36, substantiallyarched-shaped axially-buckled radially-extending annular protrusion 543is formed, which extends outwardly transverse to central axis x-x andhas at least an annular apex 544 disposed in annular groove 540 ofshroud 520.

As shown in FIGS. 33 and 36, annular groove 540 in shroud 520 has anannular obtuse first inner corner at the junction between surfaces 532and 533, and an annular obtuse second inner corner at the junctionbetween surfaces 533 and 534. Annular groove 540 also has an annularfirst outer edge with inner surface 531 of shroud 520 at the junctionbetween surfaces 531 and 532, and an annular second outer edge at thejunction between surfaces surface 534 and 535 of shroud 120.Accordingly, surfaces 532 and 534 provide groove 540 with a sloped edgedgroove, which helps to form arched-shaped axially-buckledradially-extending annular protrusion 543 disposed in annular groove 540of shroud 520 when end portion 42 of cylindrical end post 19 bucklesoutwardly into groove 540 under the applied axial ram force. As shown,groove 540 therefor comprises a generally trapezoidal cross-sectionalprofile taken in a cross-sectional plane extending radially from centralaxis x-x.

Turning now to FIGS. 37-42, a nut-type security fastener 615 accordingto a seventh example embodiment is shown. Fastener 615 has most of thefeatures of fastener 515 described above in connection with FIGS. 31-36.The major difference between fastener 615 and fastener 515 lies in thefact that annular groove 640 is formed with a generally polygonalcross-sectional profile taken in a cross-sectional plane extendingradially from central axis x-x with a chamfered outer edge.

In particular, and with reference to FIGS. 39 and 42, shroud 620 has agenerally cylindrical configuration elongated along axis x-x and isgenerally bounded by outwardly-facing horizontal cylindrical surface629, rightwardly-facing vertical annular surface 630, inwardly-facinghorizontal cylindrical surface 631, leftwardly and inwardly-facingfrusto-conical surface 632, leftwardly-facing vertical annular surface633, inwardly-facing horizontal cylindrical surface 634,rightwardly-facing vertical annular surface 635, inwardly-facinghorizontal cylindrical surface 636, leftwardly-facing vertical annularsurface 637, inwardly-facing horizontal cylindrical surface 638, andleftwardly-facing vertical annular surface 639, joined on it outsmarginal end to the left marginal end of surface 629. Surfaces 632, 633,634 and the outer annular portion of surface 635 define annular groove640 orientated transverse to axis x-x.

As shown and described with respect to fastener 515, in thepre-assembled state shown in FIG. 40, shroud 620 has been placed overleft distal end 42 of post 19 such that the outer annular portion ofrightwardly-facing annular face 635 of shroud 620 abuts againstleftwardly-facing annular end face 26 of end 42 of post 19. To completeassembly of fastener 615, with shroud 620 placed over left distal end 42of post 19 such that the outer annular portion of rightwardly-facingannular face 635 of shroud 620 abuts against and contactsleftwardly-facing annular end face 26 of end 42 of post 19 as shown inFIG. 40, an axial force is then applied with a ram to leftwardly-facingvertical annular surface 639 of shroud 620 while fastener body 16 isheld stationary in a press or the like. Such force is great enough tobuckle end portion 42 of cylindrical portion 19 into groove 640, asshown in FIGS. 41 and 42, which depict the fully assembled configurationof fastener 615. As shown, leftwardly-facing annular end face 26 of post19 is radially supported by frictional contact with rightwardly-facingannular face 635 of shroud 620 so that leftwardly-facing annular endface 26 of peripheral end 42 does not flare out. However, that portionof cylindrical end post 19 that aligns axially with groove 640 of shroud620, is not immediately supported and has thickness 53 designed tobuckle outwardly into groove 640 under the applied force to form buckledretaining arch 643. When assembled, at least apex 644 of buckled arch643 extends into groove 640, thereby retaining shroud 620 on the end ofbody 16 such that shroud 620 is free to rotate about center axis x-x ofbody 16 but is restrained from moving axially to the left off of end 42of post 19 and body 16. Thus, as shown in FIG. 42, substantiallyarched-shaped axially-buckled radially-extending annular protrusion 643is formed, which extends outwardly transverse to central axis x-x andhas at least an annular apex 644 disposed in annular groove 640 ofshroud 620.

As shown in FIGS. 39 and 42, annular groove 640 has an annular ninetydegree or squared first inner corner at the junction between surfaces633 and 634, and an annular ninety degree or squared second inner cornerat the junction between surfaces 634 and 635. Annular groove 640 alsohas an annular first outer edge with inner surface 631 of shroud 620defined by frusto-conical surface 632. Accordingly, surface 632 providesgroove 640 with a sloped edged groove, which helps to form arched-shapedaxially-buckled radially-extending annular protrusion 643 disposed inannular groove 640 of shroud 620 when end portion 42 of cylindrical endpost 19 buckles outwardly into groove 640 under the applied axial ramforce. As shown, groove 640 therefor comprises a generally polygonalcross-sectional profile taken in a cross-sectional plane extendingradially from central axis x-x with a chamfered outer edge.

Turning now to FIGS. 43-48, a nut-type security fastener 715 accordingto an eighth example embodiment is shown. Fastener 715 has most of thefeatures of fastener 515 described above in connection with FIGS. 31-36.The major difference between fastener 715 and fastener 515 lies in thefact that annular groove 740 is formed with a generally rectangularcross-sectional profile taken in a cross-sectional plane extendingradially from central axis x-x.

In particular, and with reference to FIGS. 45 and 48, shroud 720 has agenerally cylindrical configuration elongated along axis x-x and isgenerally bounded by outwardly-facing horizontal cylindrical surface729, rightwardly-facing vertical annular surface 730, inwardly-facinghorizontal cylindrical surface 731, leftwardly-facing vertical annularsurface 732, inwardly-facing horizontal cylindrical surface 733,rightwardly-facing vertical annular surface 735, inwardly-facinghorizontal cylindrical surface 736, leftwardly-facing vertical annularsurface 737, inwardly-facing horizontal cylindrical surface 738, andleftwardly-facing vertical annular surface 739, joined on it outsmarginal end to the left marginal end of surface 729. Surfaces 732, 733and the outer annular portion of surface 735 define annular groove 740orientated transverse to axis x-x.

As shown and described with respect to fastener 515, in thepre-assembled state shown in FIG. 46, shroud 720 has been placed overleft distal end 42 of post 19 such that the outer annular portion ofrightwardly-facing annular face 735 of shroud 720 abuts againstleftwardly-facing annular end face 26 of end 42 of post 19. To completeassembly of fastener 715, with shroud 720 placed over left distal end 42of post 19 such that the outer annular portion of rightwardly-facingannular face 735 of shroud 720 abuts against and contactsleftwardly-facing annular end face 26 of end 42 of post 19 as shown inFIG. 46, an axial force is then applied with a ram to leftwardly-facingvertical annular surface 739 of shroud 720 while fastener body 16 isheld stationary in a press or the like. Such force is great enough tobuckle end portion 42 of cylindrical portion 19 into groove 740, asshown in FIGS. 47 and 48, which depict the fully assembled configurationof fastener 715. As shown, leftwardly-facing annular end face 26 of post19 is radially supported by frictional contact with rightwardly-facingannular face 735 of shroud 720 so that leftwardly-facing annular endface 26 of peripheral end 42 does not flare out. However, that portionof cylindrical end post 19 that aligns axially with groove 740 of shroud720, is not immediately supported and has thickness 53 designed tobuckle outwardly into groove 740 under the applied force to form buckledretaining arch 743. When assembled, at least apex 744 of buckled arch743 extends into groove 740, thereby retaining shroud 720 on the end ofbody 16 such that shroud 720 is free to rotate about center axis x-x ofbody 16 but is restrained from moving axially to the left off of end 42of post 19 and body 16. Thus, as shown in FIG. 48, substantiallyarched-shaped axially-buckled radially-extending annular protrusion 743is formed, which extends outwardly transverse to central axis x-x andhas at least an annular apex 744 disposed in annular groove 740 ofshroud 720.

As shown in FIGS. 45 and 48, annular groove 740 has an annular ninetydegree or squared first inner corner at the junction between surfaces732 and 733, and an annular ninety degree or squared second inner cornerat the junction between surfaces 733 and 735. Annular groove 740 alsohas an annular ninety degree or squared first outer edge with innersurface 731 of shroud 720 at the junction between surfaces 731 and 732.Accordingly, arched-shaped axially-buckled radially-extending annularprotrusion 743 is disposed in annular groove 740 of shroud 720 when endportion 42 of cylindrical end post 19 buckles outwardly into groove 740under the applied axial ram force. As shown, groove 740 thereforcomprises a generally rectangular cross-sectional profile taken in across-sectional plane extending radially from central axis x-x.

While the previous embodiments have described forming a substantiallyarched-shaped axially-buckled radially-extending annular protrusionwhich extends outwardly transverse to central axis x-x and has at leastan annular apex disposed in an annular groove of the shroud by applyinga single axial force with a ram to the exposed end of the shroud whilethe fastener body is held stationary in a press or the like, more than asingle axial ramming force may be applied. FIGS. 49 and 50 show fastener715 formed after applying a second axial force with a ram to the exposedend surface 739 of shroud 720 while fastener body 16 is held stationary.Such force is great enough to further buckle end portion 42 ofcylindrical portion 19 into groove 740, as shown in FIGS. 49 and 50,such that arched-shaped axially-buckled radially-extending annularprotrusion 760 has a flattened apex 761 and substantially fillsrectangular groove 740.

Turning now to FIGS. 51-56, a nut-type security fastener 815 accordingto a ninth example embodiment is shown. Fastener 815 has most of thefeatures of fastener 615 described above in connection with FIGS. 37-42.The major difference between fastener 815 and fastener 615 lies in thefact that annular groove 840 has a cross-sectional profile taken in across-sectional plane extending radially from central axis x-x that hasa corner with a curved radius.

In particular, and with reference to FIGS. 53 and 56, shroud 820 has agenerally cylindrical configuration elongated along axis x-x and isgenerally bounded by outwardly-facing horizontal cylindrical surface829, rightwardly-facing vertical annular surface 830, inwardly-facinghorizontal cylindrical surface 831, leftwardly and inwardly-facingarcuate surface 832, inwardly-facing horizontal cylindrical surface 833,rightwardly-facing vertical annular surface 835, inwardly-facinghorizontal cylindrical surface 836, leftwardly-facing vertical annularsurface 837, inwardly-facing horizontal cylindrical surface 838, andleftwardly-facing vertical annular surface 839, joined on it outsmarginal end to the left marginal end of surface 829. Surfaces 832, 833and the outer annular portion of surface 835 define annular groove 840orientated transverse to axis x-x.

As shown and described with respect to fastener 615, in thepre-assembled state shown in FIG. 54, shroud 820 has been placed overleft distal end 42 of post 19 such that the outer annular portion ofrightwardly-facing annular face 835 of shroud 820 abuts againstleftwardly-facing annular end face 26 of end 42 of post 19. To completeassembly of fastener 815, with shroud 820 placed over left distal end 42of post 19 such that the outer annular portion of rightwardly-facingannular face 835 of shroud 820 abuts against and contactsleftwardly-facing annular end face 26 of end 42 of post 19 as shown inFIG. 54, an axial force is then applied with a ram to leftwardly-facingvertical annular surface 839 of shroud 820 while fastener body 16 isheld stationary in a press or the like. Such force is great enough tobuckle end portion 42 of cylindrical portion 19 into groove 840, asshown in FIGS. 55 and 56, which depict the fully assembled configurationof fastener 815. As shown, leftwardly-facing annular end face 26 of post19 is radially supported by frictional contact with rightwardly-facingannular face 835 of shroud 820 so that leftwardly-facing annular endface 26 of peripheral end 42 does not flare out. However, that portionof cylindrical end post 19 that aligns axially with groove 840 of shroud820, is not immediately supported and has thickness 53 designed tobuckle outwardly into groove 840 under the applied force to formasymmetrical buckled retaining arch 843. When assembled, at least offsetapex 844 of eccentric buckled arch 843 extends into groove 840, therebyretaining shroud 820 on the end of body 16 such that shroud 820 is freeto rotate about center axis x-x of body 16 but is restrained from movingaxially to the left off of end 42 of post 19 and body 16. Thus, as shownin FIG. 56, substantially arched-shaped axially-buckledradially-extending annular protrusion 843 is formed, which in thisembodiment is not symmetrical about apex 844 and which extends outwardlytransverse to central axis x-x and has at least annular apex 844disposed in annular groove 840 of shroud 820.

As shown in FIGS. 53 and 56, annular groove 840 has an annular curvedfirst inner radius corner defined by surface 832, and an annular ninetydegree or squared second inner corner at the junction between surfaces833 and 835. Annular groove 840 also has an annular first outer edgewith inner surface 831 of shroud 820 at the junction between surfaces831 and 832. Accordingly, surface 832 provides groove 840 with a curvedcornered groove, which helps to form asymmetrically arched-shapedaxially-buckled radially-extending annular protrusion 843 disposed inannular groove 840 of shroud 820 when end portion 42 of cylindrical endpost 19 buckles outwardly into groove 840 under the applied axial ramforce. As shown, groove 840 therefor comprises a cross-sectional profiletaken in a cross-sectional plane extending radially from central axisx-x with a corner having a curved radius.

Referring now to FIGS. 57-62, an improved safety fastener is provided, abolt-type embodiment of which is generally indicated at 915. Boltfastener 915 generally includes fastener body 916 and shroud 920, whichrotates about axis x-x relative to fastener body 916. Fastener body 916includes tool engaging portion 917, threaded shank 918 andshroud-retaining post 919 on which shroud 920 is rotationally supported.Fastener 915 has most of the features of fastener 515 described above inconnection with FIGS. 31-36. The major difference between fastener 615and fastener 515 lies in the fact that fastening portion 918 of fastener919 is a bolt-type fastener rather than nut type 519. Bolt fastener 915is installed in a wheel hole such that post 919 and shroud 920 arearranged to be exposed outside the entrance of the hole. The fasteningend portion 918 of bolt fastener 915 includes a shank that is externallythreaded over a portion or all of its length. The bolt fastener ismounted on wheels that have at least one fastener-receiving recess holewith threads corresponding to the threads of shank 918.

Post 919 is of the same configuration as post 519 and shroud 920 is ofthe same configuration as shroud 520. Thus, with shroud 920 placed overleft distal end 942 of post 919 such that the outer annular portion ofrightwardly-facing annular face 935 of shroud 920 abuts against andcontacts leftwardly-facing annular end face 926 of end 942 of post 919as shown in FIG. 60, an axial force is then applied with a ram toleftwardly-facing vertical annular surface 939 of shroud 920 whilefastener body 916 is held stationary in a press or the like. Such forceis great enough to buckle end portion 942 of cylindrical portion 919into groove 940, as shown in FIGS. 61 and 62, which depict the fullyassembled configuration of fastener 615. As shown, leftwardly-facingannular end face 926 of post 919 is radially supported by frictionalcontact with rightwardly-facing annular face 935 of shroud 920 so thatleftwardly-facing annular end face 926 of peripheral end 942 does notflare out. However, that portion of cylindrical end post 919 that alignsaxially with groove 940 of shroud 920, is not immediately supported andhas thickness designed to buckle outwardly into groove 940 under theapplied force to form buckled retaining arch 943. When assembled, atleast apex 944 of buckled arch 943 extends into groove 940, therebyretaining shroud 920 on the end of body 916 such that shroud 920 is freeto rotate about center axis x-x of body 916 but is restrained frommoving axially to the left off of end 942 of post 919 and body 916.Thus, as shown in FIG. 62, substantially arched-shaped axially-buckledradially-extending annular protrusion 943 is formed, which extendsoutwardly transverse to central axis x-x and has at least an annularapex 944 disposed in annular groove 940 of shroud 920. As shown, groove940 comprises a generally trapezoidal cross-sectional profile taken in across-sectional plane extending radially from central axis x-x.

Turning now to FIGS. 63-69, an improved safety fastener is provided, aninverted nut-type embodiment of which is generally indicated at 1015.Fastener 1015 generally includes fastener body 1016 and shroud 1020,which rotates about axis x-x relative to fastener body 1016. Fastenerbody 1016 includes tool engaging portion 1017, threaded fasteningportion 1018 and shroud-retaining portion 1019 on which shroud 1020 isrotationally supported.

Threaded fastening portion 1018 of fastener body 1016 includes bore 1021that is internally threaded over a portion or all of its length. Nutfastener 1015 may be installed in a wheel having a recess hole formed asa relatively deep cylindrical well. The wheel hole has an annular recessentrance and a wheel stud or post in the wheel hole, and fastener body1016 and fastening portion 1018 are sized and installed such that theinterior threads of inner bore 1021 engage the corresponding exteriorthreads of the wheel stud in the wheel hole.

Tool engaging portion 1017 of fastener body 1016 is a speciallyconfigured recess in end face 1059 having key-receiving pattern 1023 towhich a drive torque may be applied. In FIGS. 63-69, lock pattern 1023is generally in the form of a star-shaped recess. In order to impartlock pattern uniqueness, the lock pattern 1023 may be patterned in anysuitable manner, such as by employing a different recess contour, aselected number of grooves and/or by varying the spacing, width, lengthor depth of the recess or grooves.

A key (not shown) may be used to engage lock pattern recess 1023. Thekey includes a socket that is formed with a key pattern configured andarranged to be received in and engage lock pattern 1023 when the socketis properly aligned and placed into tool engaging recess 1017.

As shown in FIG. 65, retaining portion 1019 of fastener body 1016 is aspecially configured generally cylindrical surface elongated along axisx-x and is generally bounded by leftwardly-facing vertical annularsurface 1024, outwardly-facing horizontal cylindrical surface 1025,leftwardly and outwardly-facing frusto-conical surface 1026,outwardly-facing horizontal cylindrical surface 1027, rightwardly andoutwardly-facing frusto-conical surface 1028, and outwardly-facinghorizontal cylindrical surface 1029. Surfaces 1026, 1027 and 1028 defineannular groove 1040 orientated transverse to axis x-x.

Shroud 1020 extends over and around shroud receiving portion 1019 offastener body 1016. As shown, pre-assembled shroud 1020 includes innerbore 1060, having an inside diameter 1054 approximately the same size asthe outside diameter of surfaces 1025 and 1029 of shroud receivingportion 1019. With reference to FIG. 65, shroud 1020 has a generallycylindrical configuration elongated along axis x-x and is generallybounded by rightwardly-facing vertical annular surface 1030,inwardly-facing horizontal cylindrical surface 1031, leftwardly-facingvertical annular surface 1032, outwardly-facing horizontal cylindricalsurface 1033, rightwardly-facing vertical annular surface 1034,outwardly-facing horizontal cylindrical surface 1035, rightwardly andoutwardly-facing frusto-conical surface 1036 a, leftwardly andoutwardly-facing frusto-conical surface 1036 b, outwardly-facinghorizontal cylindrical surface 1037, leftwardly-facing vertical annularsurface 1038, and outwardly-facing horizontal cylindrical surface 1039,joined at its right end to the outer marginal end of surface 1030.Surfaces 1020-1039 generally form a thin-walled hollow cylindricalcolumn of inner diameter 1054 and outer diameter 1055. Shroud 1020comprise distal end portion 1042, thinned medial portion 1041 andproximate end portion 1045. End portions 1042 and 1045 have a thickness1053. However, groove 1062, defined by surfaces 1034-1038, has beenformed in medial portion 1041 such that medial portion 1041 is thinnerthan end portions 1042 and 1045 and has a reduced thickness 1057. Thus,surfaces 1034-1038 define an annular rectangular groove 1062 cut intothe middle of the outer cylindrical surface 1033 and 1039 of shroud 1020and having a center V-shaped notch 1036 defined by surfaces 1036 a and1036 b. This allows for buckling of thinned medial portion 1041 at notch1036 in groove 1062 of shroud 1020 into corresponding groove 1040 offastener body 1016.

In the pre-assembled state shown in FIGS. 66 and 67, shroud 1020 hasbeen placed over the left end of retaining portion 1019 such thatrightwardly-facing surface 1030 of shroud 1020 abuts againstleftwardly-facing annular end face 1024 of retaining portion 1019. Asshown, in this pre-assembled state, the left end of shroud 1020 extendsleftwardly a distance beyond end face 1059 of retaining portion 1019.When assembled as described below, this extension will disappear asmedial portion 1041 of shroud 1020 buckles inwardly into groove 1040 andreduces the axial length along axis x-x of shroud 1020 from end face1024 of body 1016.

To complete assembly of fastener 1015, with shroud 1020 placed over leftdistal end of retaining portion 1019 such that rightwardly-facingsurface 1030 of shroud 1020 abuts against leftwardly-facing annular endface 1024 of fastener body 1016 as shown in FIGS. 66 and 67, an axialforce is then applied with a ram to leftwardly-facing annular surface1032 of shroud 1020 while fastener body 1016 is held stationary in apress or the like. Such force is great enough to buckle medial portion1041 at notch 1036 of shroud 1020 into groove 1040 of retaining portion1019 of fastener body 1016, as shown in FIGS. 68 and 69, which depictthe fully assembled configuration of fastener 1015. Thus, fastener body1016 and shroud 1020 are specially formed such that applying a directedaxial force to shroud 1020 with a ram causes cylindrical medial portion1041 of shroud 1020 to buckle inwards into specially formed groove 1040in retaining portion 1019 of body 1016. Thus, groove 1061 with interiornotch 1036 form a thinned medial portion 1041 of cylindrical shroud 1020which aligns axially with groove 1040 of retaining portion 1019 and isnot immediately supported and has thickness 1057 designed to buckleinwardly into groove 1040 at notch 1036 under the applied force to formbuckled retaining arch 1043. When assembled, at least apex 1044 ofbuckled arch 1043 extends into groove 1040, thereby retaining shroud1020 on the end of body 1016 such that shroud 1020 is free to rotateabout center axis x-x of body 1016 but is restrained from moving axiallyto the left off of the end of retaining portion 1019 and body 1016. Ithas been found that buckled medial portion 1043 of shroud 1020 resultsin a cap assembly that requires higher tear-off forces to remove andtherefore is more secure. Thus, as shown in FIG. 69, substantiallyarched-shaped axially-buckled radially-extending annular protrusion 1043is formed, which extends inwardly transverse to central axis x-x and hasat least an annular apex 1044 disposed in annular groove 1040 ofretaining portion 1019 of fastener body 1016.

As shown in FIGS. 67 and 68, annular groove 1040 in retaining portion1019 has an annular obtuse first inner corner at the junction betweensurfaces 1026 and 1027, and an annular obtuse second inner corner at thejunction between surfaces 1027 and 1028. Annular groove 1040 also has anannular first outer edge with outer surface of retaining portion 1019 atthe junction between surfaces 1025 and 1926, and an annular second outeredge at the junction between surfaces surface 1029 and 1028 of retainingportion 1019. Accordingly, surfaces 1026 and 1028 provide groove 1040with a sloped edged groove, which helps to form arched-shapedaxially-buckled radially-extending annular protrusion 1043 disposed inannular groove 1040 of retaining portion 1019 when medial portion 1041of shroud 1020 buckles inwardly into groove 1040 under the applied axialram force. As shown, groove 1040 therefor comprises a generallytrapezoidal cross-sectional profile taken in a cross-sectional planeextending radially from central axis x-x.

Shroud 1020 is thereby mounted concentrically on retaining portion 1019of nut fastener 1015 such that it does not move axially off of retainingportion 1019 but is substantially free to rotate about axis x-x relativeto fastener body 1016.

Turning now to FIGS. 70-76, a nut-type security fastener 1115 accordingto a twelfth example embodiment is shown. Fastener 1115 has most of thefeatures of fastener 1015 described above in connection with FIGS.63-69. The major difference between fastener 1115 and fastener 1015 liesin the fact that annular groove 1140 in fastener body 1016 is to theright and aligned with end portion 1145 of shroud 1120 and groove 1161is on the right end of shroud 1120 rather than in the medial portionthereof and thereby forms a step.

In particular, retaining portion 1119 of fastener body 1116 is aspecially configured generally cylindrical surface elongated along axisx-x and is generally bounded by leftwardly-facing vertical annularsurface 1224, leftwardly and outwardly-facing frusto-conical surface1126, outwardly-facing horizontal cylindrical surface 1127, rightwardlyand outwardly-facing frusto-conical surface 1128, and outwardly-facinghorizontal cylindrical surface 1129. Surfaces 1126, 1127 and 1128 defineannular groove 1140 orientated transverse to axis x-x.

With reference to FIGS. 72 and 74, shroud 1120 has a generallycylindrical configuration elongated along axis x-x and is generallybounded by rightwardly-facing vertical annular surface 1130,inwardly-facing horizontal cylindrical surface 1131, leftwardly-facingvertical annular surface 1132, outwardly-facing horizontal cylindricalsurface 1133, rightwardly-facing vertical annular surface 1134,outwardly-facing horizontal cylindrical surface 1135, rightwardly andoutwardly-facing frusto-conical surface 1136 a, leftwardly andoutwardly-facing frusto-conical surface 1136 b, and outwardly-facinghorizontal cylindrical surface 1037, joined at its right end to theouter marginal end of surface 1130. Step 1161, defined by surfaces1034-1037, has been formed in right end portion 1145 such that endportion 1145 is thinner than the rest of shroud 1120 and has a reducedthickness 1157. Thus, surfaces 1034-1037 define an annular rectangularstep 1061 cut from the right outer edge of the outer cylindrical surface1133 of shroud 1120 and having a center V-shaped notch 1136 defined bysurfaces 1136 a and 1136 b. This allows for buckling of thinned portion1145 at notch 1136 in groove or step 1161 of shroud 1120 intocorresponding groove 1140 of fastener body 1116.

As shown and described with respect to fastener 1015, in thepre-assembled state shown in FIGS. 73 and 74, shroud 1120 has beenplaced over the left end of retaining portion 1119 such thatrightwardly-facing surface 1130 of shroud 1120 abuts againstleftwardly-facing annular end face 1124 of retaining portion 1119. Tocomplete assembly of fastener 1115, with shroud 1120 placed over leftdistal end of retaining portion 1119 such that rightwardly-facingsurface 1130 of shroud 1120 abuts against leftwardly-facing annular endface 1124 of fastener body 1116 as shown in FIGS. 73 and 74, an axialforce is then applied with a ram to leftwardly-facing annular surface1132 of shroud 1120 while fastener body 1116 is held stationary in apress or the like. Such force drives end face 1130 of shroud 1120 intoend face 1124 of fastener body 1116 and is great enough to buckle tinnedend portion 1145 at notch 1136 of shroud 1120 into groove 1140 ofretaining portion 1119 of fastener body 1116, as shown in FIGS. 75 and76, which depict the fully assembled configuration of fastener 1115.Thus, fastener body 1116 and shroud 1120 are specially formed such thatapplying a directed axial force to shroud 1120 with a ram causescylindrical thinned end portion 1145 of shroud 1120 to buckle inwardsinto specially formed groove 1140 in retaining portion 1119 of body1116. Thus, groove 1161 with interior notch 1136 form a thinned endportion of cylindrical shroud 1120 which aligns axially with groove 1140of retaining portion 1119 and is not immediately supported and hasthickness 1157 designed to buckle inwardly into groove 1140 at notch1136 under the applied force to form buckled retaining arch 1143. Whenassembled, at least apex 1144 of buckled arch 1143 extends into groove1140, thereby retaining shroud 1120 on the end of body 1116 such thatshroud 1120 is free to rotate about center axis x-x of body 1116 but isrestrained from moving axially to the left off of the end of retainingportion 1119 and body 1116. Thus, as shown in FIG. 76, substantiallyarched-shaped axially-buckled radially-extending annular protrusion 1143is formed, which extends inwardly transverse to central axis x-x and hasat least an annular apex 1144 disposed in annular groove 1140 ofretaining portion 1119 of fastener body 1116.

As shown in FIGS. 75 and 76, annular groove 1140 in retaining portion1119 has an annular obtuse first inner corner at the junction betweensurfaces 1126 and 1127, and an annular obtuse second inner corner at thejunction between surfaces 1127 and 1128. Annular groove 1140 also has anannular first outer edge with outer surface of retaining portion 1119 atthe junction between surfaces 1129 and 1128 of retaining portion 1119.Accordingly, surfaces 1126 and 1128 provide groove 1140 with a slopededged groove, which helps together with step 1161 and notch 1136 to formarched-shaped axially-buckled radially-extending annular protrusion 1143disposed in annular groove 1140 of retaining portion 1119 when thinnedportion 1145 of shroud 1120 buckles inwardly into groove 1140 under theapplied axial ram force.

Turning now to FIGS. 77-83, an improved safety fastener is provided, aninverted nut-type embodiment of which is generally indicated at 1215.Fastener 1215 generally includes fastener body 1216 and shroud 1220,which rotates about axis x-x relative to fastener body 1216. Fastenerbody 1216 includes tool engaging portion 1217, threaded fasteningportion 1218 and shroud-retaining portion 1219 on which shroud 1220 isrotationally supported.

Threaded fastening portion 1218 of fastener body 1216 includes bore 1221that is internally threaded over a portion or all of its length. Nutfastener 1215 may be installed in a wheel having a recess hole formed asa relatively deep cylindrical well. The wheel hole has an annular recessentrance and a wheel stud or post in the wheel hole, and fastener body1216 and fastening portion 1218 are sized and installed such that theinterior threads of inner bore 1221 engage the corresponding exteriorthreads of the wheel stud in the wheel hole.

Tool engaging portion 1217 of fastener body 1016 is a cavity in end face1259 having a specially configured internal profile to which a drivetorque may be applied. This internal profile comprises a key-receivingpattern that may be implemented as a set of circumferentially spacedinternally facing longitudinally extending key-receiving grooves 1223arranged in a lock pattern to which a drive torque may be applied. Inorder to impart lock pattern uniqueness, the grooves 1223 may bepatterned in any suitable manner, such as by employing a selected numberof grooves and/or by varying the spacing, width, length or depth of thegrooves. A key (not shown) may be used to engage lock pattern grooves1223. The key includes a socket that is formed with a key patternconfigured and arranged to be received in and engage lock patterngrooves 1223 when the socket is properly aligned and placed into toolengaging recess 1217.

As shown in FIG. 79, retaining portion 1219 of fastener body 1216 is aspecially configured generally cylindrical surface elongated along axisx-x and is generally bounded by leftwardly-facing vertical annularsurface 1270, outwardly-facing horizontal cylindrical surface 1271,leftwardly-facing vertical annular surface 1272, outwardly-facinghorizontal cylindrical surface 1273, rightwardly and outwardly-facingfrusto-conical surface 1274, leftwardly and outwardly-facingfrusto-conical surface 1275, outwardly-facing horizontal cylindricalsurface 1276, rightwardly-facing vertical annular surface 1277, andoutwardly-facing horizontal cylindrical surface 1278. Surfaces 1271 and1272 define left annular step 1225 orientated transverse to axis x-x andsurfaces 1277 and 1278 define right annular step 1226 orientatedtransverse to axis x-x. Surfaces 1274 and 1275 define annular recess1228 orientated transverse to axis x-x. Recess 1228 in body 1216 reducesthe weight and material needed to form body 1216 and reduces frictionalcontact that might limit rotational movement of shroud 1220 about body1216.

Shroud 1220 extends over and around shroud receiving portion 1219 offastener body 1216. With reference to FIG. 81, pre-assembled shroud 1220has a generally cylindrical configuration elongated along axis x-x andis generally bounded by rightwardly-facing vertical annular surface1230, inwardly-facing horizontal cylindrical surface 1231,leftwardly-facing vertical annular surface 1232, inwardly-facinghorizontal cylindrical surface 1233, leftwardly-facing vertical annularsurface 1234, outwardly-facing horizontal cylindrical surface 1235,rightwardly and outwardly-facing frusto-conical surface 1236 a,leftwardly and outwardly-facing frusto-conical surface 1236 b,outwardly-facing horizontal cylindrical surface 1237, leftwardly-facingvertical annular surface 1238, and outwardly-facing horizontalcylindrical surface 1239, joined at its right end to the outer marginalend of surface 1230. The inner annular portion of surface 1230 andsurfaces 1231 and 1232 form right annular flange 1245. Step 1262,defined by surfaces 1032-1037, has been formed in right end portion 1242such that end portion 1242 is thinner than the rest of shroud 1220 andhas a reduced thickness 1257. Thus, surfaces 1035-1037 define an annularrectangular step 1262 cut from the left outer edge of the outercylindrical surface 1239 of shroud 1220 and having a center V-shapednotch 1236 defined by surfaces 1236 a and 1236 b. This allows forbending and buckling of thinned portion 1245 at notch 1236 in step 1262of shroud 1220 into corresponding step 1225 of fastener body 1216.

In the pre-assembled state shown in FIGS. 80 and 81, shroud 1220 hasbeen placed over retaining portion 1219 such that leftwardly-facingsurface 1232 of shroud 1220 abuts against rightwardly-facing annular endface 1227 of retaining portion 1219. Thus, right annular flange 1245 isseated in right annular step 1226 such that shroud 1220 is restrainedfrom moving left along axis x-x relative to fastener body 1216. Asshown, in this pre-assembled state, the left end 1242 of shroud 1220extends leftwardly a distance beyond end face 1270 of retaining portion1219. When assembled as described below, this extension will disappearas end portion 1242 of shroud 1220 bends and buckles inwardly into step1225 and reduces the axial length along axis x-x of shroud 1220.

To complete assembly of fastener 1215, with shroud 1220 placed overretaining portion 1219 such that leftwardly-facing surface 1232 ofshroud 1220 abuts against rightwardly-facing annular end face 1227 ofretaining portion 1219 and right annular flange 1245 is seated in rightannular step 1226 as shown in FIGS. 80 and 81, an axial force is thenapplied with a ram to leftwardly-facing annular surface 1234 of shroud1220 while right annular flange 1245 seated in right annular step 1226are both held stationary in a press or the like. Such force is greatenough to bend and buckle end portion 1242 at notch 1236 of shroud 1220into step 1225 of retaining portion 1219 of fastener body 1216, as shownin FIGS. 82 and 82, which depict the fully assembled configuration offastener 1215. Thus, thinned end portion 1242 of cylindrical shroud 1220aligns axially with step 1225 of retaining portion 1219 and is notimmediately supported and has thickness 1257. It is configured to buckleoutwardly and bend inwardly into step 1225 at notch 1236 under theapplied force to form axially-buckled radially-extending annular endportion 1244 bent inwardly transverse to central axis x-x and disposedin annular step 1225 of shroud-receiving body portion 1219. Whenassembled, annular bent portion 1244 is seated in annular step 1225,thereby retaining shroud 1220 on the end of body 1216 such that shroud1220 is free to rotate about center axis x-x of body 1216 but isrestrained from moving axially to the right off of retaining portion1219 and body 1216. Thus, as shown in FIG. 83, axially-buckledradially-extending annular end portion 1244 is formed, which is bentinwardly transverse to central axis x-x and is disposed in annular step1225 of shroud-receiving body portion 1219 of fastener body 1216.

Shroud 1220 is thereby mounted concentrically on retaining portion 1219of nut fastener 1215 such that it does not move axially off of retainingportion 1219 but is substantially free to rotate about axis x-x relativeto fastener body 1216.

Turning now to FIGS. 84-90, a nut-type security fastener 1315 accordingto a fourteenth example embodiment is shown. Fastener 1315 has most ofthe features of fastener 1215 described above in connection with FIGS.77-83. The only difference between fastener 1215 and fastener 1215 liesin the fact that thinned portion 1342 is on the right annular end ofshroud 1320 and annular flange 1345 is on the left annular end of shroud1320.

In particular, in the pre-assembled state shown in FIGS. 87 and 88,shroud 1320 has been placed over retaining portion 1319 such that leftannular flange 1345 is seated in left annular step 1225 such that shroud1320 is restrained from moving right along axis x-x relative to fastenerbody 1216. As shown, in this pre-assembled state, the right end 1342 ofshroud 1320 extends rightwardly a distance beyond the end of step 1226of retaining portion 1219. When assembled as described below, thisextension will disappear as end portion 1342 of shroud 1320 buckles andbends inwardly into step 1226 and reduces the axial length along axisx-x of shroud 1320.

To complete assembly of fastener 1315, with shroud 1320 placed overretaining portion 1219 such left annular flange 1345 is seated in leftannular step 1225 as shown in FIGS. 87 and 88, an axial force is thenapplied with a ram to rightwardly-facing annular surface 1334 of shroud1320 while left annular flange 1345 seated in left annular step 1225 areboth held stationary in a press or the like. Such force is great enoughto bend and buckle end portion 1342 at notch 1336 of shroud 1320 intostep 1226 of retaining portion 1219 of fastener body 1216, as shown inFIGS. 89 and 90, which depict the fully assembled configuration offastener 1315. Thus, thinned end portion 1342 of cylindrical shroud 1320aligns axially with step 1226 of retaining portion 1219 and is notimmediately supported and has thickness 1357. It is configured to buckleoutwardly and bend inwardly into step 1226 at notch 1336 under theapplied force to form axially-buckled radially-extending annular endportion 1344 bent inwardly transverse to central axis x-x and disposedin annular step 1225 of shroud-receiving body portion 1219. Whenassembled, annular bent portion 1344 is seated in annular step 1226,thereby retaining shroud 1320 on the end of body 1216 such that shroud1320 is free to rotate about center axis x-x of body 1216 but isrestrained from moving axially to the left off of retaining portion 1219and body 1216. Thus, as shown in FIG. 90, axially-buckledradially-extending annular end portion 1344 is formed, which is bentinwardly transverse to central axis x-x and is disposed in annular step1226 of shroud-receiving body portion 1219 of fastener body 1216.

Shroud 1320 is thereby mounted concentrically on retaining portion 1219of nut fastener 1215 such that it does not move axially off of retainingportion 1219 but is substantially free to rotate about axis x-x relativeto fastener body 1216.

Turning now to FIGS. 91-97, a nut-type security fastener 1415 accordingto a fifteenth example embodiment is shown. Fastener 1415 has many ofthe features of fastener 1215 described above in connection with FIGS.77-83. The biggest difference between fastener 1415 and fastener 1215lies in the fact that both annular ends of shroud 1420 have thinnedportions 1442 and 1445.

In particular, in the pre-assembled state shown in FIGS. 94 and 95,shroud 1420 has been placed over retaining portion 1419 such that leftthinned annular end 1442 of shroud 1420 is aligned axially with leftannular step 1425 of retaining portion 1419 of body 1416 and rightthinned annular end 1445 of shroud 1420 is aligned axially with rightannular step 1425 of retaining portion 1419 of body 1416, such that theleft end 1442 of shroud 1420 extends leftwardly a distance beyond theend of step 1425 of retaining portion 1519 and the right end 1445 ofshroud 1420 extends rightwardly a distance beyond the end of step 1426of retaining portion 1419. When assembled as described below, theseextensions will disappear as end portion 1442 of shroud 1420 buckles andbends inwardly into step 1425 and end portion 1445 of shroud 1420buckles and bends inwardly into step 1426, reducing the axial lengthalong axis x-x of shroud 1420.

To complete assembly of fastener 1415, with shroud 1420 placed overretaining portion 1419 as shown in FIGS. 94 and 95, opposed axial forcesare then applied with opposed rams simultaneously to rightwardly-facingannular surface 1434 of shroud 1320 and leftwardly-facing annularsurface 1333 of shroud 1320. Such forces are great enough to buckle andbend end portion 1442 at notch 1436 of shroud 1420 into step 1425 ofretaining portion 1419 of fastener body 1416 and buckle and bend endportion 1445 at notch 1466 of shroud 1420 into step 1426 of retainingportion 1419 of fastener body 1416, as shown in FIGS. 96 and 97, whichdepict the fully assembled configuration of fastener 1415. Thus, thinnedend portion 1442 of cylindrical shroud 1420 aligns axially with step1425 of retaining portion 1419 and is not immediately supported and hasthickness 1457 and thinned end portion 1445 of cylindrical shroud 1420aligns axially with step 1426 of retaining portion 1419 and is notimmediately supported and has thickness 1457. These annular ends areconfigured to buckle and bend or curl inwardly into steps 1425 and 1426,respectively, at notches 1436 and 1466, respectively, under the appliedforce to form axially-buckled radially-extending annular end portions1443 bent inwardly transverse to central axis x-x and disposed inannular step 1425 of shroud-receiving body portion 1419 andaxially-buckled radially-extending annular end portions 1444 bentinwardly transverse to central axis x-x and disposed in annular step1426 of shroud-receiving body portion 1419. When assembled, annular bentportion 1443 is seated in annular step 1425, thereby retaining shroud1420 on body 1416 such that shroud 1420 is free to rotate about centeraxis x-x of body 1416 but is restrained from moving axially to the rightoff of retaining portion 1419 and body 1416 and annular bent portion1444 is seated in annular step 1426, thereby retaining shroud 1420 onbody 1416 such that shroud 1420 is free to rotate about center axis x-xof body 1416 but is restrained from moving axially to the left off ofretaining portion 1419 and body 1416. Thus, as shown in FIG. 97,axially-buckled radially-extending annular end portion 1443 is formed,which is bent inwardly transverse to central axis x-x and is disposed inannular step 1425 of shroud-receiving body portion 1419 of fastener body1416, and axially-buckled radially-extending annular end portion 1443 isformed, which is bent inwardly transverse to central axis x-x and isdisposed in annular step 1426 of shroud-receiving body portion 1419 offastener body 1416.

Shroud 1420 is thereby mounted concentrically on retaining portion 1419of nut fastener 1415 such that it does not move axially off of retainingportion 1419 but is substantially free to rotate about axis x-x relativeto fastener body 1416.

The components of the embodiments of the fastener may be formed ofvarious different materials. For example, and without limitation, steel,stainless steel, brass, aluminum and titanium may be used. As anotheralternative, and without limitation, non-metallic materials may be usedin some applications. In some applications, and without limitation, thecap or shroud may be of a material harder than the lock body. Forexample, and without limitation, the spin cap or shroud may have ahardness range from about 36 Rockwell C to 55 Rockwell C and the lockbody may have a hardness less than the hardness of the spin cap. Thehardness of the spin cap may be less than about 40 Rockwell C. Withoutlimitation, in certain applications the volume of material deformed andmoved to fill the corresponding annular groove may be about 30% orhigher.

In addition, the fastener may be designed using certain boundaryconditions shown below. The first constraint governs, with reference tothe first embodiment 15 as an example and without limitation, the insidediameter 54 of post 19. The second constraint governs the strength ofthe buckle zone (buckle 43 formed from medial portion 41) of post 19relative to the non-buckle zone (distal end portion 42 and proximateportion 45) of post 19. The third constraint governs the tubeslenderness ratio of the post.

Variable Definitions

1=axial length of groove (23)D₁=outside diameter of crush post (19) (reference 55 in FIG. 4)D₂=inside diameter of crush post (19) (reference 54 in FIG. 4)H=difference in height of post pre/post assembly (reference 51 in FIG.4)k=relationship factor ratio between allowable tensile and sheer stressesT=input torque required for lockF=resulting force needed to torque lockRT=resulting offload torque (what the post has to support)LH₁=length of L-handle from center of rotation to force applicationLH_(d)=length of L-handle from center of axial traverse rotation toforce applicationσ_(RT,post)=resulting stress in post from off axis torque during lockinstallationTA=tensile stress in postSA=shear stress in buckled region of post

Initial Problem Definition—Relationships

  σ_(TA, max ) = σ?$\mspace{20mu} {{k->{{relation}\mspace{14mu} {factor}}} = {\frac{{ultimate}\mspace{14mu} {tensile}}{{ultimate}\mspace{14mu} {shear}} = \left( {0.5,0.8} \right)}}$?indicates text missing or illegible when filed

Solving for Constraint 1

$\begin{matrix}{{T = {\left. {F*{LH}_{\iota}}\Rightarrow F \right. = \frac{T}{{LH}_{l}}}}{{RT} = {F*{LH}_{d}}}{\sigma_{{RT},{post}} = {{\frac{32*{RT}*D_{1}}{\pi*\left( {D_{1}^{4} - D_{2}^{4}} \right)}\mspace{14mu} {{from}(1)}\mspace{14mu} D_{2}} = \left( {D_{1}^{4} - \frac{32*{RT}*D_{1}}{\sigma_{{RT},{post}}*\pi*\left( {D_{1}^{4} - D_{2}^{4}} \right)}} \right)^{1/4}}}} & (1)\end{matrix}$

Solving for Constraint 2

${TA} = {\frac{\pi}{4}\left( {D_{1}^{2} - D_{2}^{2}} \right)*h}$SA = π * l * D₁ * h * k set  SA ≥ TA${\frac{\pi}{4}\left( {D_{1}^{2} - D_{2}^{2}} \right)*h} \geq {\pi*l*D_{1}*h*k}$

Reduces to

${\frac{1}{4}\left( {D_{1}^{2} - D_{2}^{2}} \right)} \geq {l*D_{1}*k}$$D_{2} \geq \sqrt{D_{1}^{2} - {4*l*D_{1}*k}}$

Reduces to

D ₂≧√{square root over (D ₁*(D ₁−4*l*k))}

Constraint 3 (Assumed)

D ₂≦0.95*D ₁

The present invention contemplates that many changes and modificationsmay be made. Therefore, while forms of the improved fastener have beenshown and described, and a number of alternatives discussed, personsskilled in this art will readily appreciate that various additionalchanges and modifications may be made without departing from the scopeof the invention, as defined and differentiated by the following claims.

What is claimed is:
 1. A fastener comprising: a fastener body orientated about a central axis; said fastener body having a tool-engaging portion to which a driving torque may be applied and a threaded fastening portion configured and arranged to mate with a corresponding threaded element; said fastener body having a shroud-receiving body portion orientated about said central axis; a shroud concentrically mounted on said shroud-receiving body portion and having an inner surface facing an outer surface of said shroud-receiving body portion; said shroud being supported in rotatable relationship with said shroud-receiving body portion such that said shroud will rotate relative to said fastener body under an applied external torque prior to said fastener body rotating when said fastener is engaged with an external structure at a design installation torque; said inner surface of said shroud comprising an annular groove orientated transverse to said central axis; said shroud-receiving body portion comprising a substantially arch-shaped axially-buckled radially-extending annular protrusion extending outwardly transverse to said central axis and having at least an annular apex disposed in said annular groove of said shroud; and said substantially arch-shaped axially-buckled radially-extending annular protrusion of said shroud-receiving body portion and said annular groove of said shroud forming a shroud-retaining element restraining said shroud from movement in at least a first axial direction along said central axis.
 2. The fastener of claim 1, wherein: said shroud-receiving body comprises a thin-walled cylindrical tubular portion having an annular first body surface, and an annular shoulder having an annular second body surface; said shroud comprises an annular shoulder portion having an annular first shroud surface, and an annular second shroud surface; and said first body surface faces said first shroud surface and said second body surface faces said second shroud surface.
 3. The fastener set forth in claim 2, wherein said second body surface of said shroud-receiving body and said second shroud surface of said shroud are in an opposing orientation and form a second shroud-retaining element restraining said shroud from movement in at least a second axial direction along said central axis opposite to said first axial direction along said central axis.
 4. The fastener set forth in claim 3, wherein an end portion of said thin-walled cylindrical tubular portion of said shroud-receiving body that is adjacent said annular first body surface of said shroud-receiving body is supported radially by an opposed inwardly-facing cylindrical surface of said shroud such that said end portion of said thin-walled cylindrical tubular portion of said shroud-receiving body is restrained from deforming radially outwardly from said central axis by said opposed inwardly-facing cylindrical surface of said shroud.
 5. The fastener set forth in claim 4, wherein said annular groove of said shroud extends into a medial portion of said inner surface of said shroud between said first shroud surface and said second shroud surface.
 6. The fastener set forth in claim 5, wherein said shroud-retaining element is formed by an axial buckle of a medial portion of said thin-walled cylindrical tubular portion of said shroud-receiving body radially into said annular groove of said shroud.
 7. The fastener set forth in claim 6, wherein said axial buckle of said medial portion of said thin-walled cylindrical tubular portion of said shroud-receiving body is formed by a compressive force applied axially to said thin-walled cylindrical tubular portion of said shroud-receiving body by said first shroud surface of said shroud.
 8. The fastener set forth in claim 1, wherein said groove of said shroud comprises an annular first inner corner, an annular second inner corner, an annular first outer edge with said inner surface of said shroud, and an annular second outer edge with said inner surface of said shroud.
 9. The fastener set forth in claim 8, wherein said annular first inner corner and/or said annular second inner corner of said groove comprises a frusto-conical surface or a radial surface.
 10. The fastener set forth in claim 8, wherein said annular first outer edge and/or said annular second outer edge of said groove comprises a frusto-conical surface or a radial surface.
 11. The fastener set forth in claim 1, wherein said annular groove of said shroud comprises a trapezoidal, triangular or semi-circular cross-section taken in a plane extending radially from said central axis.
 12. The fastener set forth in claim 1, wherein said groove of said shroud is substantially U-shaped or V-shaped.
 13. The fastener set forth in claim 1, wherein said substantially arch-shaped axially-buckled radially-extending annular protrusion of said shroud-receiving body portion is asymmetrical.
 14. The fastener set forth in claim 1, wherein said substantially arch-shaped axially-buckled radially-extending annular protrusion of said shroud-receiving body portion is substantially U-shaped or V-shaped.
 15. The fastener set forth in claim 1, wherein said fastener body comprises a lock nut or a lock bolt.
 16. A fastener comprising: a fastener body orientated about a central axis; said fastener body having a tool-engaging portion to which a driving torque may be applied and a threaded fastening portion configured and arranged to mate with a corresponding threaded element; said fastener body having a shroud-receiving body portion orientated about said central axis; a shroud concentrically mounted on said shroud-receiving body portion and having an inner surface facing an outer surface of said shroud-receiving body portion; said shroud being supported in rotatable relationship with said shroud-receiving body portion such that said shroud will rotate relative to said fastener body under an applied external torque prior to said fastener body rotating when said fastener is engaged with an external structure at a design installation torque; said outer surface of said shroud-receiving body portion comprising an annular groove orientated transverse to said central axis; said shroud comprising a substantially arch-shaped axially-buckled radially-extending annular protrusion extending inwardly transverse to said central axis and having at least an annular apex disposed in said annular groove of said shroud-receiving body portion; and said substantially arch-shaped axially-buckled radially-extending annular protrusion of said shroud and said annular groove of said shroud-receiving body portion forming a shroud-retaining element restraining said shroud from movement in at least a first axial direction along said central axis.
 17. The fastener of claim 16, wherein: said shroud-receiving body portion comprises an annular shoulder having an annular body surface; said shroud comprises an annular first shroud surface and an annular second shroud surface; and said first shroud surface faces said body surface.
 18. The fastener set forth in claim 17, wherein said body surface of said shroud-receiving body portion and said first shroud surface of said shroud are in an opposing orientation and form a second shroud-retaining element restraining said shroud from movement in at least a second axial direction along said central axis opposite to said first axial direction along said central axis.
 19. The fastener set forth in claim 17, wherein an end portion of said shroud that is adjacent said first shroud surface of said shroud is supported radially by an opposed outwardly-facing cylindrical surface of said shroud-receiving body portion such that said end portion of said shroud is restrained from deforming radially inwardly toward said central axis by said opposed outwardly-facing cylindrical surface of said shroud-receiving body portion.
 20. The fastener set forth in claim 17, wherein said shroud-receiving body portion comprises an annular second body end surface and said annular groove of said shroud-receiving body portion extends into a medial portion of said outer surface of said shroud-receiving body portion between said body surface and said second body surface.
 21. The fastener set forth in claim 20, wherein said shroud-retaining element is formed by an axial buckle of a medial portion of said shroud radially into said annular groove of said shroud-receiving body portion.
 22. The fastener set forth in claim 21, wherein said axial buckle of said medial portion of said shroud is formed by a compressive force applied axially to said annular second shroud surface of said shroud.
 23. The fastener set forth in claim 16, wherein said shroud comprises a thinned tubular cylindrical portion axially aligned with said annular groove of said shroud-receiving body portion and said shroud-retaining element is formed by an axial buckle of said thinned tubular cylindrical portion of said shroud radially into said annular groove of said shroud-receiving body portion.
 24. The fastener set forth in claim 23, wherein said thinned tubular cylindrical portion of said shroud comprises an annular crease and said annular apex of said shroud-retaining element is formed by an axial buckle of said thinned tubular cylindrical portion of said shroud at said annular crease radially into said annular groove of said shroud-receiving body portion.
 25. The fastener set forth in claim 16, wherein said groove of said shroud-receiving body portion comprises an annular first inner corner, an annular second inner corner, an annular first outer edge with said outer surface of said shroud-receiving body portion, and an annular second outer edge with said outer surface of said shroud-receiving body portion.
 26. The fastener set forth in claim 25, wherein said annular first inner corner and/or said annular second inner corner of said groove comprises a frusto-conical surface or a radial surface.
 27. The fastener set forth in claim 25, wherein said annular first outer edge and/or said annular second outer edge of said groove comprises a frusto-conical surface or a radial surface.
 28. The fastener set forth in claim 16, wherein said annular groove of said shroud-receiving body portion comprises a trapezoidal, triangular or semi-circular cross-section taken in a plane extending radially from said central axis.
 29. The fastener set forth in claim 16, wherein said groove of said shroud-receiving body portion is substantially U-shaped or V-shaped.
 30. The fastener set forth in claim 16, wherein said substantially arch-shaped axially-buckled radially-extending annular protrusion of said shroud is asymmetrical.
 31. The fastener set forth in claim 16, wherein said substantially arch-shaped axially-buckled radially-extending annular protrusion of said shroud is substantially U-shaped or V-shaped.
 32. The fastener set forth in claim 16, wherein said fastener body comprises a lock nut or a lock bolt.
 33. A fastener comprising: a fastener body orientated about a central axis; said fastener body having a tool-engaging portion to which a driving torque may be applied and a threaded fastening portion configured and arranged to mate with a corresponding threaded element; said fastener body having a shroud-receiving body portion orientated about said central axis; a shroud concentrically mounted on said shroud-receiving body portion and having an inner surface facing an outer surface of said shroud-receiving body portion; said shroud being supported in rotatable relationship with said shroud-receiving body portion such that said shroud will rotate relative to said fastener body under an applied external torque prior to said fastener body rotating when said fastener is engaged with an external structure at a design installation torque; said outer surface of said shroud-receiving body portion comprising an annular step orientated transverse to said central axis; said shroud comprising an axially-buckled radially-extending annular end portion bent inwardly transverse to said central axis and disposed in said annular step of said shroud-receiving body portion; and said bent end portion of said shroud and said annular step of said shroud-receiving body portion forming a shroud-retaining element restraining said shroud from movement in at least a first axial direction along said central axis.
 34. The fastener of claim 33, wherein: said shroud-receiving body portion comprises a second annular step; said shroud comprises an annular flange disposed around said annular step of said shroud-receiving body portion; and said second annular step of said shroud-receiving body portion and said annular flange of said shroud form a second shroud-retaining element restraining said shroud from movement in at least a second axial direction along said central axis opposite to said first axial direction along said central axis.
 35. The fastener set forth in claim 33, wherein said shroud comprises a thinned tubular cylindrical portion axially aligned with said annular step of said shroud-receiving body portion and said shroud-retaining element is formed by an axial buckle of said thinned tubular cylindrical portion of said shroud radially around said annular step of said shroud-receiving body portion.
 36. The fastener set forth in claim 35, wherein said thinned tubular cylindrical portion of said shroud comprises an annular crease and said shroud-retaining element is formed by an axial buckle of said thinned tubular cylindrical portion of said shroud at said annular crease.
 37. The fastener of claim 33, wherein said shroud-receiving body portion comprises a second annular step and said outer surface of said shroud-receiving body portion comprises an annular notch or recess between said annular step and said second annular step.
 38. The fastener of claim 33, wherein: said outer surface of said shroud-receiving body portion comprises a second annular step orientated transverse to said central axis; said shroud comprises a second axially-buckled radially-extending annular end portion bent inwardly transverse to said central axis and disposed around said second annular step of said shroud-receiving body portion; and said second bent end portion of said shroud and said second annular step of said shroud-receiving body portion form a second shroud-retaining element restraining said shroud from movement in at least a second axial direction along said central axis opposite to said first axial direction along said central axis.
 39. The fastener of claim 38, wherein said shroud comprises a thinned tubular cylindrical portion axially aligned with said second annular step of said shroud-receiving body portion and said second shroud-retaining element is formed by an axial buckle of said thinned tubular cylindrical portion of said shroud radially around said second annular step of said shroud-receiving body portion.
 40. The fastener set forth in claim 39, wherein said thinned tubular cylindrical portion of said shroud comprises an annular crease and said second shroud-retaining element is formed by an axial buckle of said thinned tubular cylindrical portion of said shroud at said annular crease.
 41. The fastener set forth in claim 33, wherein said fastener body comprises a lock nut or a lock bolt.
 42. A method of forming a fastener comprising the steps of: providing a fastener body orientated about a central axis; said fastener body having a tool engaging portion to which a driving torque may be applied, a threaded fastening portion configured and arranged to mate with corresponding threaded element, and a shroud-receiving body portion orientated about said central axis; providing a shroud; mounting said shroud concentrically on said shroud-receiving body portion such that an inner surface of said shroud faces an outer surface of said shroud-receiving body portion; axially aligning an annular groove in said inner surface of said shroud or said shroud receiving body with a buckling portion of said other of said shroud or said shroud-receiving body portion; restraining said fastener body from moving in a first direction along said central axis; applying an axial force to said shroud or said shroud-receiving body in said first direction such that said buckling portion buckles inwardly or outwardly into said annular groove under said applied axial force to form a substantially arch-shaped axially-buckled radially-extending annular protrusion extending transverse to said central axis and having at least an annular apex disposed in said annular groove; such that said shroud is restrained from movement in at least one axial direction along said central axis that is opposite to said first axial direction. 